Hi, and welcome to my jungle Rammus guide. I'll first explain the basics of the Armordillo, and then take an indepth look of what this tanky jungler can offer a team.

You may think: Why the hell is this guy writing another guide about Rammus? Well, I've realised the top rated guides about Rammus actually describe lane Rammus, who is NOT viable at the moment AT ALL. He can't harass, he can't farm at lane, he'll just be pwnd. In addition, I don't find the jungle Rammus guides quite optimal either, so I thought of doing one myself. Of course, this guide is succeptible to suggestions and changes.

17/11/2011:
Masteries changed. Masteries edited as well.
Added pictures in the Jungling chapter.
Added new chapter: Ganking techniques.
Added new chapter: Problematic champs.
Added new chapter: Teamfight

Why choosing Rammus at all, when you can choose opfftanks like Gangplank, Nocturne or Lee Sin, or ranged gankers like Amumu or Fiddlesticks? Well, Rammus isn't an offtank, but still deals tons of damage (above all against AD carries) and can get twice the hits others do without flinching at all. He's one of the best gankers in the game: The fact that people don't play him that much doesn't mean that he ganks worse than Amumu, just the opposite, in my opinion.

Pros:

+ Quite fast and sustainable jungler.

+ Epic ganks. Taunt + some skill + minimal coordination = free kill 100%

+ Really tanky. In late game can just take every enemy ult and still fight.

+ Ridiculous turretdive. Above 150 armor at level 5.

+ AoE ult with sustained damage, usefull for turretpushing/destroying.

+ Amazing speed within jungle. Can be in every lane in short time.

+ Longest targeted CC in the game. Can make fastmoving but squishy char's life a hell. (Kass, Ez, etc)

+ No AD carry can duel you. You're their worst nightmare.

+ He doesn't need 2nd blue at all, like some other junglers.

+ He can spin.

+ Has spikes.

Cons:

- Not the fastest jungler. First round goes quite fast, but then...

- Easy to counterjungle (1st blue dependant).

- Creeps can be a pain. Requires skill and thinking when ganking (and sometimes flash).

- As the intiator of TF can get easily kited as he has to be near the enemy to taunt him.

- Not the imba Atmog combo (it actually works, but not the same IMO).

- Weaker against non-autoattacker enemies.

- His voice just so low. Even a fart is louder.

So, let's begin with the runes. At the top of the guide i've added a sample set of runes that work really great with Rammus. His W scales with armor, so that Greater Mark of Armor and Greater Seal of Armor are just amazing, not only for his jungling, but for the late-game presence too. Rammus is weaker against magic damage, so adding Greater Glyph of Magic Resist is the best choice. Quints are just your call. I've added Greater Quintessence of Health as Quints are really hard to get due to their high prize, and these just work on everything, so you can just have them in every Rune Page you have. Armor Pen, Armor, Movement speed, and a bunch of others work as well.

Actually, the only runes you REALLY need are the Greater Mark of Armor, which I really recommend to buy for both jungler and AD bruiser at lane. The other can be changed with better or worse results, but will make the jungling still viable.

PS: Runes and pages are sooo fu***ng expensive! Don't make a page for just one char, you have various options, that's why I explain it so detailedly.

After testing the new masteries, I've decided that the best setup is 0/21/9. Actually, the new stuff greatly improves both the jungling speed and sustainability of the common route, so jungle Rammus is more competitive than ever. Above all, the movement speed buff from both paths and the epic damage and CC reduction from the defense path are just perfect for Rammus.

So, now we can really begin the champion itself. In this section you will (hopefully) understand why the skill sequence must be the posted above, and can't be another.

Pasive: Spiked Shell

Rammus' shell grants him additional strength by converting (25)% of his Armor into Attack Damage.

This pasive is just amazing for both jungling and ganking. The percentage armor converted into AD is dynamic, that means, Defensive Ball Curl does add you AD while active, so that your jungling becomes even more powerful. (Armor + bonus AD + Damage returned). You easily reach 200 AD or more, and it makes the ATMOG combo viable, as commented before.

Powerball

Rammus accelerates in a ball towards his enemies, dealing (100 / 150 / 200 / 250 / 300) (+(1 per ability power point)) magic damage to nearby enemies on impact and slowing them by (20 / 25 / 30 / 35 / 40)% for (3) seconds.

Activating Defensive Ball Curl will remove this effect.

This is what allows you to literally rush through the jungle. As you realise, the damage scaling is not high without building AP, and the slow duration is the same at all levels. (3 secs at lvl 1 WTF!? xDD) That's the reason it should be maxed last. You want this to make your jungling faster by reaching the camps earlier and dealing some AoE damage, and that's why you take it second, but leave it there. The acceleration is progressive, so most times it is usefull to stay in the bush spinning and then rush into the lane with 450+ movement speed after 1 o 2 seconds.

In previous versions, this ability couldn't be activated when being in Defensive Ball Curl. Riot fixed it so that one can now instantly change from Defensive Ball Curl to Powerball, which is nice as everything goes faster.

Defensive Ball Curl

Rammus goes into a defensive formation for (6) seconds, increasing his Armor and Magic Resist by (50 / 75 / 100 / 125 / 150) and returning (20 / 30 / 40 / 50 / 60) (+(0.25 per ability power point)) magic damage to attackers.

This ability gains damage equal to (10)% of Armor.

Activating Powerball will remove this effect.

This is the ability what makes Rammus so well known. Press W and just take all the damage you can. Without items, you will have above 200 resists, which is just CRAZY. Plus, you're dealing damage to autoattackers, and not a small amount, as it scales with armor, just as his pasive. This ability can deal around 150 damage per autoattack to EVERY enemy attacker, which is just nonsense. Carries just die by attacking you. Why maxing it? Puncturing taunt + Defensive Ball Curl, epic damage output. Turretdive is everytime a viable option. You aren't susceptible to ganks in the jungle. You're just imba xD

Puncturing taunt

Puncturing Taunt

Rammus taunts the unit into a reckless assault, reducing their Armor by (10 / 15 / 20 / 25 / 30) and forcing them to attack Rammus for (1 / 1.5 / 2 / 2.5 / 3) second(s).

This is your bread and butter. The armor debuff is a nice addition, but it's not the main goal. Think of any other targeted CC with 3 secs duration. Now think that its CD is 12 secs. Note that it has 325 range. Really, this is OP. It prevents carries to attack your team. This + the damage bouncing of Defensive Ball Curl and Thornmail just melt enemy carries, without even using your ultimate. It works even when enemies Flash (if they were close enough an instant before), so that even Flash doesn't save people from this guy's ganks. They'll call you hacker, noob, or they just say WTF? BUG! No bug, the armordillo es #1.

Tremors

Rammus creates tremors beneath him, dealing (65 / 130 / 195) (+(0.3 per ability power point)) magic damage every second to nearby units and structures for (8) seconds.

This ability just gives you a really high AoE damage that makes you able to kill a lot of enemies just on your own. 1600 AoE damage, that also damages structures and you're supposed to be a true tank. 1600 damage, tank? Somethin' wrong? Not wrong, maybe op! Its CD is 60 secs, not that high, and combined with your taunt, guarantess high damage output that will secure almost any gank you do.



As you realise, Rammus is a tank, but deals tons of damage (Phreak's copyright). He doesn't actually need his ult to gank successfully most of the times, so that's the reason I think it just outclasses many other junglers.

So, now that we know the basics of the character, we can begin with interesting (and most difficult to master) jungling part. Although he can do various rutes, beginning at blue it's the one that allows you to level up faster and gank ASAP, so we'll see this route.



But Cloth Armor, 5 Health Potion and head to the Blue Golem. Ask for a pull (doesn't have to be a skill, can be a mere AA), and if some laner can hit it 4 or 5 times it will make a difference. Spam Defensive Ball Curl, use 1 Health Potion, Smite and take your buff.
You should be level 2 by now.

Get Powerball, activate it and head to the Wolf camp. You have to target the ground behind the wolves to hit them with Powerball, and this is the rule against every jungle minion, so remember it. Spam Defensive Ball Curl and Powerball as much as you can, and when the big wolf dies, take your second pot. Head to the Wraiths (with Powerball).

Same method as with wolves, focus the blue wraith, they'll actually die more or less at the same time thanks to your Defensive Ball Curl. Take level 2 Defensive Ball Curl and head to the Golem Camp.

As we did before, kill them with the same spamming method. Take your 3rd Health Potion while the first golem dies. Save your Smite.

Go to the Red Lizard. Kill it as we did with the other creeps, take the 4th Health Potion when the 3rd depletes and use Smite. You should be level 4 now, and you must take Puncturing Taunt.



If your Blue Golem was ganked and u can't have it, you can go this alternative path:



The ganking techniques are the same, but you'll need more times to gank, as this route is slower.


----

And now, it's ganking time. If your HP is kinda low, take the 5th Health Potion, but it shouldn't be the case, you'll use it later (you got it for something, of course, haven't forgotten about it). Depending of your base, you will be either behind Dragon or Baron Nashor. Now you have to decide which lanes to gank, which isn't always that easy.

If bot lane is pushed, just forget it. Your taunt is only 0,5 secs long and the turret is just in front of you. They'll have Flash ready 95% of the times, and their support will take care for ganks as a lot of junglers gank at level 4. If your bot lane is being pushed by the enemy team, they just gave you the easiest and safest gank ever. They are squishy, they are underleveled, and your carry has Exhaust ready. First blood is your main goal in this case, but, just don't go mad. Follow these steps:

Ask for Clairvoyance if posible to control your enemies steps in the lane (sometimes bushes are annoying). You must be aware of the creeps that may block as well. You also can realise if they placed early ward bot (they'll run back in panic), and you can react in time by predicting their movement path, and even use Flash if necessary to secure the kill.

Actually, both support and carry are posible kills, so that you have decide the one you're going to target with Puncturing Taunt, and you have like 1 sec to make that decission. Remaining HP, positioning and posible CC's are the criteria you should follow. The more you jungle, the better you'll be able to decide who to kill.

Ping the one you finally decide to taunt, so that you focus that bastard. Puncturing Taunt + Red Buff + Powerball slow + Exhaust + some other CC (of the support or the carry or both) will secure the kill.

Congratulate your mates if the gank was successfull and go back (unless some gank in mid lane is CLEARLY feasable at sight). You need some items. Even if the gank resulted in no death, they had to retreat in the lane and most likely use Flash, so they lost a lot.

----

But you may be at the top half of the map or your bot lane could be pushed too far away. Where do we go now? Mid lane? Top lane? Both lanes will be more or less the same level, and as strong solo champions, their damage output is usually quite high. Ganking mid is always viable, and usually advisable as people tend to take really problematic chars for mid lane. Kassadin, Sion, Morgana, for example. Normally, none of them will have the lane pushed at this moment of the game, rather be in a draw.
Mid lane is REALLY vulnerable to ganks as there are like a 100 ways to gank someone there. Using Flash is always advisable, as having early game advantage in mid lane is one of the priorities when jungling. Just don't forget 3 things:

Ping before you go in.
Take in mind that their jungler can be nearby as well. We're just sooooo greedy!
Congratulate your mate if he did well.

---

But mid lane could be pushed as well. Or the mid lane char you have is rather weak this early game, he just wants to farm peacefully. (e.g. Veigar) You're in the top half of the map or you're in the bottom half, but bot is way too pushed (bastards ¬¬). Head to top lane then, you have that Powerball for something, don't be lazy!

The unique thing about top lane is that these ganks result either in a kill or in a double kill 90% of the cases. Top laners are normally so strong chars that when a real fight starts there, really crazy things happen. Usually the other jungler is there as well, or arrives some secs later, mid laner can go as well... However, Rammus excells at his speed at ganking, so don't get nervous.

Check the lane with Clairvoyance, ping, go.

Ganks in top are usually more difficult than in mid for 2 reasons. First, AP mages are the ones with greater burst: give them 1 sec to cast, and someone will die, whereas top laners deal the same (or even more) damage, but need more time. Besides, they are tankier as well and have some type of really strong CC or some powerfull movement/gap closer ability (e.g. Nasus or Irelia) Usually you'll have to burn your Flash to get those last autoattacks you need to secure the kill. NEVER turretdive with Flash unless they have less than 40 HP.

---

Why did I overextend so much in the part of the 1st gank? Well, as we said before, Rammushas nice jungling speed, but only at the beginning, so that if you need to keep creeping to get gold, the other jungler will slowly overlevel you. You actually have to be ganking all lanes as much as you can as that's your main source of gold: always check them, and if they need cover, just take some creeps there, it'll help as well. How, when and where to gank depends now from the game, so I can't guide you through your next ganks. Now it's when the jungling experience really makes the difference.

However, if you want to learn more about advanced jungling, there are some really good and extensive guides about general jungling in this website. Just check them, really worth it.

We already new the basics of the first gank, but to success in ganking you need to know how to position yourself. A couple of pictures will be helpful here.

Standard ganks:

Normally you'll try to follow these paths to gank your lanes. They're standard for every jungler, and you generally don't risk much: You don't take damage from turrets and you don't need to use Flash. However, in competitive games, people are really defensive and place Vision Ward, so a lot of them can fail.
However, no matter how much map awareness they have, if you rush with Powerbal, they won't have time to retreat, so a gank is feasable even in that case.

Advanced Ganks:

These paths are risky. Either your take damage from turret or you need to use Flash to intiate. However, they're really effective, as nobody expects you to come directly from behind. Free kill is always worth the effort.

Further tips:

- Powerball lasts for about 8 seconds, accelerating over time. If you're in position to gank, you can avoid the enemies dodging you by waiting with Powerball activated. You'll get to them much faster, and the surprise factor will be bigger.

- Puncturing Taunt can move your enemies out from turret range. With it, you can turn a riesky turretdive into an easy kill. If your enemy is barely in turret range, he'll believe he's safe, but he isn't.

- Soaring Slam damages units around you even if you activate Powerball: It isn't interrupted. If you're chasing a low health enemy, it's somtimes better to not hit them with Powerball until the very end, so that you take advantage of your high damaging ulti.

The fact that the first item in the build is Thornmail can strike some people, and I guess it'll lead to some discussion. In this section I'll explain why I buy this item and not Wriggle's Lantern like any other jungler.



+100 Armor UNIQUE Passive: On being hit by basic attacks, returns 30% of damage taken as magic damage.

+ +100 Armor, wetdream for Rammus.

+ Damage bouncing + Defensive Ball Curl + Puncturing Taunt = AD nightmare really early.

+ Turretdive is just a joke after getting this.

+ After getting it you won't need more armor so you can buy HP and Magic Resist to balance your tankiness.

+ Improves your jungling speed considerably.

- Not really expensive, but not easy to get either.

- You're still vulnerable to magic damage early on.

- No ward.

- Early dragon kill/control is more difficult.

+ The 500 damage proc really improves the jungling, more than THORNMAIL

+ Free ward every 3 mins. Just op ability.

+ Cheaper to get, so it can lead to some early advantage.

+ Better early dragon control.

- Lifesteal and Damage won't be of much use.

- Damage output in ganks is considerably lower --> Can lead to faling ganks (unacceptable for jungle Rammus!)

- You'll still need more Armor items, almost 90% of the times you'll end up buying Thornmail anyway...

- Turretdive not that easy.


So, all in all, I see more pros in getting Thornmail than Wriggle's Lantern, and that's the reason my standard build priorizes this item for a standard game. However, in the next section I will show a bunch of builds (rather different, actually) that work as well, both having pros and cons.

--- Balanced Rammus ---

Build cost: 14135 G
Health: 2195
Armor: 145
MR: 151
Mana: 375
AD: 0
AP: 0
Other stats: Damage bouncing, Sunfire's damage aura, increased movement speed, spell shield, CC reduction.

--- Panzermus! ---

OR OR OR


Build cost: Between 13890 G and 14985 G
Health: 2170
Armor: Between 265 and 319
MR: 0 or 25
Mana: 0 or 500
AD: 83
AP: Between 0 and 100
Other stats: Damage bouncing, Sunfire's damage aura, Attack/movement speed reduction (active/pasive), 2 secs invulnerability, critical chance, CC reduction.

--- Atmog-Standard Rammus ---

Build cost: 13880 G
Health: 2195
Armor: 190
MR: 75
Mana: 375
AD: 83
AP: 0
Other stats: Damage bouncing, Sunfire's damage aura, critical chance, CC reduction, spell shield.

--- Supportimmus? ---

[


Build cost: 13675 G
Health: 1095
Armor: 174
MR: 146
Mana: 875
AD: 8
AP: 70
Other stats: Fastest movement speed, armor, MR, AD and HP aura, enemies' MR reduction, attack speed reduction, Sunfire's damage aura, spell shield.

--- Carrymmus O_o ---

OR


Build cost: 12675/12680 G
Health: 450 or 950
Armor: 145 or 195
MR: 177
Mana: 375
AD: 0
AP: 150 or 170
Other stats: Damage bouncing, Sunfire's damage aura, spell shield, CC reduction, enemies' MR reduction, movement speed reduction through spells, 2 secs invulnerability.

The builds posted in the section above are just the ones I really recommend. I've tested all of them and all work REALLY well. The difference between them are significant, and therefore Rammus should be played diferently according to the items.

However, it is posible, viable, and sometimes really advisable to get items that are not included in the builds above. Let's see them.



90% of the games you'll get Mercury's Treads when facing a balanced team. If not, Ninja Tabi. However, if your team is getting brutally kited by the enemy carries, getting these boots can be usefull to taunt that bastard and merciless slay him. Sometimes Mercury's Treads are just not enough against kiting.



You may want to purchase this if you're building AP Carrymmus. It gives you a lot of stats that you need for that build. CDR, mana regen and a nice amount of AP + his incredible active, that will allow you to severely damage that target you want to kill fast. If your team is lacking damage, this is an option to consider.



This item can actually be included in almost every build, as the addtional HP and AP is a nice combination of stats for the armordillo. This can replace [Warmog's Armor so that you're still very tanky, but adding some nice damage.



This item gives you a nice amount of HP + a really lame slow through auttoattacks. If your taunt is not enough for your team to kill the targets, this can be purchased as a solution. I actually prefer Rylai's Crystal Scepter as it slows enemies within Soaring Slam, but this is nice as well.



I'm not a fan of this item but it is the only item that gives your armor + MR at the same time, so it can be really worth it buying it and balance your resists. The pasive is quite lame, but I don't think it is the most important part of the item.



Warmog is very expensive. I am imba, I'm pro, we kill and they just don't have the damage to kill me. If you think you can reach the 20 stacks, get it. 15% of damage reduction WTF? With 20 stacks, you won't have the same HP as having Warmog's Armor on you, but you'll take less damage and will end up being even tankier. But if you don't reach the 20 stacks...



Malzahar, Warwick, Skaner, Ashe, Alistar. OMFG, I just can't get to Ashe and she rapes us from the distance. Epic CC in enemy team, it's a real nightmare. Get this item, and feel like a pirate! (HUEHUEHUEHUE) Take your vengeance.



Generally you'll get this if you're going for the Supportimmus build. I didn't include this as this item is normally taken by the "real" support, and having 2 of them is kinda stupid. If he took other items, just consider to take it.



Quite similar to Shurelya's Battlesong. It gives you a nice amount of HP + an aura for mates. However, it is not the best aura in the game and it's prize isn't that low...



You can take this if you're going for the Atmog Rammus. You'll deal more damage, be faster, slow people, etc. However, it is REALLY expensive, so your build will be hard to get. However, we all know Atmog + Trinity Force combo works on every char in this game, so it works on Rammus as well. I find it quite boring getting the same combination with every char, though...



AP and spellvamp for your team. Well, its a bit of trolling but it actually works xD Soaring Slam will give you a nice amount of HP back, and your team will appreciate it. However, usually the AP carry takes it...



Kinda similar to Trinity Force. You are going for an offtank Rammus, and this item is just great for both jungling and ganking for its prize. However, most chars like Udyr or Trundle get more damage from this as they're AA based, and you aren't. Test it, and then decide whether it is worth it.



Se the Thornmail vs. Wriggle's Lantern section to see the Pros and Cons of this item.

Although ganking with Rammus is really effective and pretty deadly, there are a bunch of champs that usually require more skill and positioning when ganking them at lane. I'll try to give here some tips.

Alistar: Well, it's not that Rammus has problems with this tanky support, but all junglers have problems with him. No matter what your approach is, his 2 CC make his carry almost untouchable. If at least he was squishy himself, but he isn't, just the opposite. Try to make him use his Headbutt before you go in, or unless the lane is well pushed, ganking will be difficult.

Blitzcrank: Lately, he is being played mostly as support as well. His CC's aren't so strong as Alistar's, but he can pull you to the turret and his silence deals REAL damage. Care your positioning, never overextend when ganking his lane. Take this in mind as well if he's top lane soloing.

Brand: Brand has a 2 secs stun that if landed on you will 70% of the times completely ruin your gank. He differs Annie and Anivia, which also have stuns, in that the CC duration is considerably longer, which really makes a difference (therefore both female mages aren't quoted as problematic above). He need to target Sear, so try to dodge it. Don't go in a straight line, try to predict his movements. He doesn't have that much time to stun you, so it shouldn't be that difficult. Care from his Pyroclasm as it can instakill your mid laner if you missposition.

Caitlyn: She generally pushes lanes, which is awesome for you, but has a tendency to place Yordle Snap Trap in key places. Just check them or just gank lane fastly without going into bushes. Should be pretty easy.

Cassiopeia: Before level 6, real easy kill. Afterwards, care from her Petrifying Gaze, she can deal real nice damage in that time.

Cho'Gath: Real tanky, hard to kill. If you evade Rupture you can severly damage/kill him. Just evade that. Turretdiving... remember his TRUE damaging Feast.

Dr. Mundo: After level 6 he is ungankable for most people. Nobody plays him, so, who cares? xD

Fizz: I just have the feeling he's going to be problematic. Preparing a place for him xD

Galio: Very similar to Cho'Gath. Evade Resolute Smite, don't turretdive with less than 300 armor.

Gangplank: He's OP, so he's a problem for everyone, both as a jungler as a laner. The hairy pirate has a slow, a free Cleanse, a small but consistent Ghost and a global ult. Not only he's really a pain to gank, but can screw a gank at some other lane with his Cannon Barrage. Really, ban this bastard.

Garen: His Courage can make him really tanky when he needs it, and his Decisive Strike is pretty long silence. In addition, Perseverance usually makes him to be with high HP. Is your top laner is a nice char, however, a couple of attempts should bring him down, not that problematic.

Gragas: He can farm from the distance, Body Slam has pretty short CD and can go through every wall and his Explosive Cask just screwes every positioning and can be used defensively as well. However, he tends to be overconfident, so take that in your advantage. Take in mind that his Body Slam won't save him from Puncturing Taunt, just as Flash doesn't.

Irelia: Also a problem for almost everybody. Her pasive is really amazing and can heal pretty fast with Trascendent Blades. Her Equilibrium Strike is kinda perfect against ganks, and that makes turretdiving really risky as well. However, she's squishier than it semms early game. A couple of early ganks will bring her down.

Janna: If she's really good Janna, then her strong CC will make ganking hard. However, she's not like Alistar. Is you get to her, she's as easy to kill as the carry she's protecting. A kill is a kill.

Kassadin: This guy is a problem if he has 2 things: Level 6 and the blue buff. But before that, he's really easy to gank. He won't be full HP, and one Puncturing Taunt, and he's dead. If he doesn't Flash, it's a kill, if he does, just next gank is a kill.
I actually take Rammus as a counter to Kassadin. His Puncturing Taunt will make teamfight for him really hard, as your target will be always him, and if you do, he's dead. If your ganks in lane were successfull, he'll need a lot of time to recover, so you can focus on someone else for a while.

Katarina: Short CD Flash. Apart from that, she's not problematic, just try to be in the middle of her Shunpo] so she falls even after casting it. If she sees herself in trouble, she'll cast [[Death Lotus, so care the damage.

Kennen: Real headache for most junglers. He can stun you 3 times in a row, has Lightning Rush to escape unharmed and can deal real burst damage. If you come from behind...

Kog'Maw: He's the only carry that, if fed, can kill you 1 vs 1, but only if fed. Just wanted to point that out, don't overextend or he'll get another kill and be LEGENDARY xD

LeBlanc: Pretty similar to Kassadin. The difference is she's even squishier, but has Flash before. Real counter, like against Kassadin IMO.

Lee Sin: As a jungler, he can enter a fight before you even realise he's there and deal epic damage and score a double kill, but this can happen against every jungler. As a top laner, his Safeguard/Iron Will makes him fast moving, and Dragon'r Rage will drive you to another planet. He's really stron, like Gangplank

Lux: Just dodge that Light Binding. GG, free kill.

Morgana: Real strong char, her CC is pretty amazing. If you successfully dodge her Dark Binding, her Black Shield will prevent her from getting any enemy CC, WTF? Ganking her is posible, but will require epic coordination, so that she loses some of these advantages before engaging.

Nidalee: Gank before level 6 is really easy, generally free kill. Afterwards, she moves real fast, so it's a pain for most junglers.

Olaf: The Ragnarok rework made him just imba now. He deals true damage as well and heals pretty fast. He'll be tough to get down, but his aggresivity in lane will make him die eventually.

Singed: He's so tanky. Has CC, CC reduction and movement speed, so ganking is difficult for everybody. If you've got real burst top, he'll be easier target.

Skarner: Tanky, heals, moves fast, has a shield and Impale can turn into a turret death. The same applies for his jungling. Burst him down before he can spam abilities.

Swain: Try to gank before level 6, and evade Nevermove. After level 6, he'll be tankier, but ganking him isn't that difficult either.

Talon: Check Kassain or Katarina, pretty similar mechanics.

Vayne: Condemn works amazingly well against Rammus ganks. Combined with Alistar it's a real dizzy lane.

Warwick: Don't turretdive...

Wukong: His Warrior Trickster interrupts your Powerball, which is a pain. Care if turretdiving, he deals consistent damage and can have Cyclone.

Zilean: After level 6, he just casts Cronoshift on himself and nothing happened. So lame xDD

As a tough char, you can intiate teamfights with Powerball pretty well. If you combine it with Flash correctly, so that you catch one of their carries, then you'll win that fight.

However, it isn't that easy to reach their carries in competitive games. In those cases, initiating with Powerball is too obvious, and they'll fall back inmediately. Therefore, try to coordinate your teammates so that you go all together. Why? Well, the enemies also want to kill your carries. If you stay relatively close to them, you will be able to target Puncturing Taunt fast and without moving much, so that they'll be the ones dying, and not your carries.
Always remember: Protecting your carries is as important as killing the enemy ones. Your main target is the fragile AD carry, as you can kill him within the Puncturing Taunt duration WITHOUT help, so that the rest of the team can focus on the other enemies. However, that doesn't mean you completely ignore the other carries.

So, to sum up: Positioning is 99% in teamfight. Most of the games are lost because people missposition.