Hello litlle fellows of league of legends, it's my first guide and its going to be about the awesome DR.Mundo.
Im a bit of a jungler, I mean, im not a newbie but not also a pro, just a common player, but I think I got this, so let's begin with some useful things.

First of all you need to think about what mundo has and what is he meant to do.

-Well MR.Mundo has a lot of Damage, Damage, and Damage, but that's not all, he also gots the awesome W that gives you not only a freaking lots of AoE damage to clear the jungle but also a hardcore way to escape CC, maybe at early it's hard to get away using this skill but well, when you got enough HP-Regen you gonna rock and roll and be and douchebag against mages and supports that think they can stun you.

-Mundo has one of the greatest jungling skill, the Cleaver, it's so good it's impossible to nerf it. The awesomeness of this skill is the fast jungling that provides, you can clear the dragon alone in secs at low levels, and the buffs are going to cry when you hit them with this little one.

-Talking about mundos W and Q it's simply great, but we can't forget about the massive E, it gives so much damage you can own that careless jungler that's trying to counter you (nobody counters mundo), yep if he gets in your way you can blow away his head with awesome Q, W and E combination dealing a massive damage in like well 1 sec. This Skill also helps you to clear even faster the camps, and if you go counter and you find the as*h*** that's stealing your part of the jungle (both jungles belong to mundo) you can bring him pain and death and get back your buffs.

Apart from jungling this should be a great way of using your Q. (OLD BUT GOLD)

-Well all mundo pre 6 skills are freaking awesome but most of people gets wet when they use the R, you know that sh*t is great, but it's easy countered with an simply ignite, you can use it to: run, chase, troll, dive, and initiate, but if you take all the damage and an ignite and your support can't save you from that situation better don't do anything at all to initiate, just spam Q. R is great in so many ways, you can jungle for ever after lvl 6, and if you're good enough you can get lvl 6 without going "B", so you can jungle forever and go back with 2-3k gold if you farm and the other jungler leaves you be.

Here ends the things you must know about Mundo before starting R***** the jungle and the other jungler.

Well, this isn't so tricky, and hard to see.

Magic Pen: Helps a lot to clear camps faster and even maybe kill someone, remember the way of mundo to kill is using W and staying next to someone without getting killed.

AP: Faster clearing, it also gives some extra damage on W. This can be changed on what you preffer.

Armor and MR: You really need this, helps a lot to jungle and to gank, if you gank withouth armor or MR you're going to get killed easy as a full ap teemo diving. You can change the MR per level to flat MR for early ganks if you feel confident.

Well, that should be your full build, you can make changes to it if you think the game needs them, maybe a Frozen Mallet or maybe a Spirit Visage who knows, maybe you dont even need to do Aegis if your support already got it, but its good to get some support items so you help a lot and allow him to buy something else better for his lane.

Maw of Malmortius Ninja Tabi and Warmog's Armor are your core, you can't go without them, you get ninja tabi cause you already have CC reduction from your W, Maw Of Malmortius grants you even more damage, you become a hard hitter, and a shield is great, Warmog's is mundo's item, it's simply all that mundo needs. All other items can be replaced if you see better options.
Starting
There's two ways to start.
Boots and Health Potionx3. It's still one of the best choices.

But if you lack of confidence or skill you should get.
Cloth Armor and Health Potionx5. Great Sustain, simply as that.

New items, well, Mundo doesn't need the machete at all, but if you wanna give it a try, good luck. Anyways you should get that faster as possible, cause it enchances your E.

After clearing camp twice you should ganked at least once, and now you must get Kage's Lucky Pick, why?, well cause there's no more Heart of Gold, and you want cheap wards, get it, also it gives you some extra speed cleaning camps cause of the AP. You should sell this item as fast as you don't need it more or you need to replace it, if you want you can evolve it, but I don't think it's the best choice.

Skill sequence is very easy, really.

W E Q R
That's the basic, try to get the max W as fast as you can, then balance between e and q, whenever you can level your ulti, that's all you need.

Well, there are mainly two combinations of summoner spells for Mundo.

First of all there's the one I use and I think it's the best.
Smite Exhaust

Why? and Why Not?

Exhaust: Well its easy, Mundo has a skill shot that slows but if you fail your gank becomes useless, so if you want a sure gank or maybe even kill, you use exhaust, no need of skill shot practice and no need of even trying hard, it makes ganks lot easier. Conclusion: Great spell, but may become useless sometimes or against some champs, the usefulness of this comes from how you use it so think about it before rambling into a fight and releving into Exhaust.

Smite: Isn't that obvious?, you're the jungle, you need it, even if you can clear all the camps without it you need it to steal, and make sure you get the baron or drake or whatever your team needs. Conclusion: You need it, that's all, but if you fell enough pro, change it for something better, like Clean or Ignite.

There's also another way of summoner spells combination.
Smite Flash

Why? and why not?

Smite: I told you about this a moment ago so no point in repeating.

Flash: Well, that's actually one of the best spells of all the game, it gives you lot of mobility that maybe save your life or make you do great thinks like go into baron and steal to maybe dive and go away easily, but I think it's no the best option for mundo, he has the R to dive, and diving early is freaking hard right now with that armor pen towers, so no point in trying and failing and also feeding with a tower dive. Conclusion: Flash is great in many ways, but well, it's more personal choice, if you're better with this combo use it, but if not, use Exhaust.

PROS

• Fast Jungler

• Hard to Counter jungler

• One of the most hated champs to play against

• Really easy to kill the other jungler if you counter jungle

• Easy to Snowball in counter jungle

• Not that expensive items

CONS

• Hard to Sustain if you're not good enough

• Easy Countered with ignite

• Skill Shot based ganks

• doesn't make you inmortal

• If you lose jungle once you're done, that's all, you lost.

PROS

• Helps a lot your support to get other items and so better teamfights.

• Even as support deals a lot of damage.

• Still Tanky.

• It's Mundo.

• Ganking with most of the time is a free kill.

• Impossible to kill with and .

CONS

• Obviously less damage than normal mundo.

• Need to stay with your team a lot and so lose a bit of farm.

• Counterjungling is gonna be a bit harder.

• Worse duelist than normal mundo.

Jungling Route

• Wraiths

• Red

• Golems

• Wraiths again

• Wolfs

• Blue

Mundo is really a very versatile champ, he can be a great team fighter but also a great duelist, at low levels as I said he can destroy the other jungler easily, even if he has a lot of CC.

In team fight Mundo should be the initiator or the second to go, and chase the ADC and the AP Carry, nothing more matters than getting rid of these two, your brutal damage should make them cry when you hit them.

Be careful with the ignites and exhausts, they can make you a free kill, if there's much of this or you cant handle the stuns, well you should think about changing some item for a Mercurial Scimitar.

Remember your W makes you a pain for everyone except your team, use it and also the Randuin's Omen.

Well here's the end of my guide, its very simple and short, it's not an in-deepth guide, it's just good enough to know how to play a basic mundo, there are a lot of better guides but I think this is the easiest to read, cause it's short and it doesn't speak about metagame or hard to understand stuff.

Thanks all for reading, even if you vote possitive or negative I must say Thanks for giving some time to see this.

If someone want's to comment something that helps the guide or to discuss something, feel free to do it.

Updates

• 11/05/13:
  • Separated full build from starting items to get real stats, added a few builds options.
  • Added Fancy lists cause everybody loves fancy lists.
  • Added a chapter of pros and cons of support mundo jungler.
  • Looking for flaws in my english (still doing it).