I should begin giving you thanks for see that build. Excuse me, I am a spanish dude and my English is just ok. Once u look into this guide, I just hope u learn 4 things about udyr, an amazing champion little hard to manage in the begining. There are some mates that posted their guides and I learned a lot of them, but in this guide I will offer another point of view, because most of people see udyr like an hybrid dps/tank (and that's right because he is able to ^^), so I will suggest two different builds, of pure dps and tank. Thats not right in all matches but in a balanced team you can do it and its more funny and usefull from my point of view. I am not trying to get votes, I am only trying that u fall in love with that champion like I am. Once i said that let's see why anyone of u would want to choose udyr or just want it in their team.

Udyr could be seen as a complicated guy hard to manage. That's why he do a lot of functions thanks to his 4 skills, so you must be patient and learn when you have to use each one and the basic rotations.

As a dps, udyr can do horrible burst dps with tiger stance, enough to 3 second kill in late game to squisy champions without any survival item like yi, annie, twisted fate, you know... and catch them if they try to run, using your high movement speed, bear stance stun, finish them with another tiger stance. Then, is nice to stay in the brush to instant kill the poor man he walks through or enter the initiated fight to finish that dangerous dps champions that kills your casters or just gang with your insane movement speed and stun+burst combo that I will explain later.

Being a tank your function is annoy their whole team with your bear stance, mittigate all posible dmg and support your team to focus squisy champions and stop dangerous chanelling ultimates like fiddlesticks's, kattarina's and similar. My build has a decent hp/armor/magic resist combinated with cc disablers, that allows you to absorb many damage and ignore crowd control to let you stun them right. You got a decent dps because of the item build, that's why other team will want to finish you (that not happens with most tanks) and the more focus and cc you receive, the less threat for your own team (its obvious) but your function is not to do damage so u can take it well, giving your team time to eliminate one by one the other team dangerous champions.

Both builds are though to play like a jungler, what gives u more gold and xp, same that your mate that will be alone vs 2 (be sure that there are 2 champions on your team that cant be solo, mid and top/bot).

Let's explain those things detailed.

Pros:
-Insane burst dmg in late game and movement speed (dps)
-Nice survival
-Great ganker hero
-Can jungle
-Very versatile

Cons:
-Hard to manage
-Jungle dependent (low mana and mana reg., imposible to harass)
-Vulnerable to cc (realy like everybody >.<)

Udyr is very mana dependent early game, so we will begin taking the blue buff (your own golem if there is another jungle champion in the other team or their golem if they havent, avoiding that common ganks in the begining). To be able to kill it (lvl 1) we will need:
-phoenix stance: learn it and start the fight with it, be sure that the waves hit the golem and dragons and spam it every time u have the cooldown
-cloth armor: buy it first, because it makes you hard enough to resist and later you will use it to buy-hp potion: spend the rest of the money in hp potions. Use it just after you are hit by the golem
-Smite: use it on the golem after use phoenix stance

Once u kill the golem use another potion and learn turtle stance. Then go to kill the wolves (remember phoenix+turtle+phoenix, you will use that combo until lvl 5 in dps build and always in tank build). Once they fall use another potion and kill the mages (then you will be lvl 3), use another potion and go for the red buff.

There is not more mistery, you just have to remember:
-The rotation
-Keep the blue buff on you
-Turn back to buyand boots after
-If the solo lane die, go to that tower and wait untill you mate come back

Try to gank mid (priority) or lanes at lvl 6/7 with boots, goost, red buff and starting with bear stance (u can see that I learn it soon with both build but dont use it to farm, now you know why). That ganks use to finish with 1 or 2 enemy champions dead or forces them to use invoker spells to scape (heal, flash, exhaust, ghost) if they have it, so even if they can scape, the large cd on that skills will make it easy for your mates keep pushing or kill them after.

It's not a bad idea to put a ward in the dragon. That prevents bot/mid to be ganked, be sure that you won't be ganked while u kill it and destroy any jungler champion that is trying to kill it and let you do it then. If you are the one that want to gain that gold be sure to have:
-The blue buff
-One hp potion
-Lvl 7+
-Madred's razors
-It helps a lot to have the boots finished

To gank you will need:
-Ghost ready
-Boots of speed
-A Good Chance(obviously dont gank a line where your mate/s havent enough life to fight or the enemy/s has too much hp and a survival summoner spell [specially flash])
-The red buff
-lvl 5+, what means you have bear stance

There is a point when u take more benefit farmin in lane that jungling, that's not at a lvl like 7 or 12, it is (for me) when you have got madred's bloodrazors and the boots u chose (use to be lvl 8-9). Now you will go to jungle just to take mana buff (or red) and kill the dragon everytime he spawns, you will farm spamming tiger/phoenix stance if you are dps/tank. But farm isn't everything, try to farm a side and gank another, take a buff and gang, push a solo lane, keep a side while your mate come back to heal, but I will give you an advice: I've said that farm isn't everything, but being udyr is more than half ;)

DPS BUILD:
-: what to say, glyphs give too poor ofensive bonus for udyr so that magic resist will help you for gank early game. CD reductions are good too but i think it dont make it a real difference.
-: will help you in the jungle phase, because more atack speed means more phoneix effectiveness (remember that it jump every 3 atacks under that state empowering the 3ºhit with bonus dmg and splash). Mid and early game it grants you more hits using, (what is OUCH). I wouldn't even think about change that mark for anyone, but somebody prefers armor penetration for more burst dmg, and they have their reasons (works nice too).
-: thats what I choose for myself, because it helps me in the jungle phase but u can easy change it for health/lvl, avoidance, armor, or even more atack speed.
-: more atack speed? YES, THANKS. As i said before, armor penetration works well too, even movement speed or health.

TANK BUILD:

-: magic resist for your tank? Yes, thanks!
-: the same i said on dps runes.
-: that means less hits from monster in the begining, what helps a lot, and of course, mid and late game, a hit avoided in a fight gives you a speed buff because of deffensive masterys, helping to scape or using bear stance faster to anoy them
-: I have explained it before too. NOW, you can change it for movement speed, that works nice too. I just prefer %atack speed because it helps me in jungle phase too.

I have said before that we will always begin withand hp potions, following withand boots. Now I will tell you how i continue my build depending of what roll i want to (DAMAGE DEALER).

Boots: here you will have to choose. You can try to pick Berserker boots for more Burst, but I use to makefor more survival, pick it vs teams with tosome Crowd Control (remember the more u stay alive and moving the more dmg you will do). Rarely I chooseor, i dont recomend them. The one YOU choose, consider it as a CORE ITEM
: it gives armor, one never has enough armor = ). It gives AD and ASpeed but the reason I take razors is that the pasive bonus on atack does combo with tiger stance bonus atack speed. It does terrifying dmg even to tanks. CORE ITEM
: I rly LOVE this item, its not expensive and has all in one. That will give us ASpeed, our needed armor penetration, first %Crit, little CD reduction (trust me, you will feel it) and of course, the active bonus.
When in activate it u turn in Chuck Norris state, empowering your 2 basic weapons in a gank: movement speed and ASpeed. Try to use combinate with ghost and bear stance and once your target is stunned, change to tiger and make him fall under 10000 hits in a row with madred's razors. CORE ITEM

-: what can i say from this item, u know all that it's expensive but trust me you will pawn. More ASpeed, %Crit, MS, AD, proc to slow and best skill "on cast" to reduce your opponent to small pieces of champion. CORE ITEM

We have got two more slots: we have to choose between survival items or more dps, it depends of the type of match and how much caster and crowd control the enemys have or how much dmg is your team able to do.

-Defensive Items:gives hp, MR and protection for nukes and ccis the cheapest option, gives MR and cc protection, rly a nice item (if you dont forget to activate ¬¬ its a joke, i know you have hands)nice item and cheap too, casters will hate you. I use to pick hexdrinker vs casters without cc skills.

-Offensive Items:
There is a large number of options we have in this point.usefull vs tanks with lot of hp and armorimproves our dmg with ASpeed and %Crit, but more important is the bonus MS, great to catch that yi, teemo, sivir etcit makes combo with madred's and your insane ASpeed to make you become the Nightmare of every caster (that uses mana, ofc)your best friend to do burst dmg, you do crazy dmg using itthe lifesteal items, needed if your enemys have champions with lot of hp or THORNMAIL, otherwise the fight will be too long and you won't be able to stay alive enough time. Choose the first if there is not more AD champions on your team and Stark fervor if you got more mates AD dependant. Finally chooseif there is a sivir, jax or tank with ninja tabi (probably with masterys and runes of evasion too) and his face will turn to (o.ó: ****)

I have said before that we will always begin withand hp potions, following withand boots. Now I will tell you how i continue my build depending of what roll i want to (TANK).

Boots: you have got an easy choice,orCORE ITEM
: it gives you armor, ASpeed, AD and his pasive bonus on hit will make u do a decent dmg so if they dont want to focus the tank of your team (YOU) they will pay it with stuns from your bear stance and that dmg bonus and your phoenix/tiger stance, but trust me they will pay atention for you, otherwise they wont be able to coordinate, use chanelling skills or similar. CORE ITEM
: the bonus AD does not feel but the hp bonus is great and his passive "on hit" will disrrupt them a lot, so its nice to tank, gank or teamfights, combinated with bear stance. CORE ITEM
: just WONDERFULL, armor and magic ressist neccesary for a tank, and its great on udyr because he dont works with large cd, he use low cds too annoy the other team and do a decent amount of dmg while doing it, so what happens if they achieve to defeat you? nothing! because u turn alive again and still disrupting them. CORE ITEM

Now we need to adapt our udyr to the match we are playing with 2 more items. We have to be very flexible. Choose them between:

Offensive: rarely we will take more offensive items but you have to pay attention to see if your team needs to do more dmg, so you could buy(one or even two),empowers your shield and phoenix dmg, protects you and makes your enemys vulnerable to magic dmgsimilar to abyssal scepterif their dps dont has any armor/hp item

Auras: if your team need cd reductions, speed to catch the runners (its horrible when they always scape with 100 hp), armor pen. life steal and ASpeed
Armor/Magic resist: it depends of what kind of game are yoy playing vs. If they have got too much cc useor. If they are AP DPS your item isand if they do physicall DMG you will have to pickand, both give armor, cd reduction and an annoyer skill. A risky option is make, think that since you use udyr as tank you must be in every gank and teamfight helping and giving assist and that could help you to take charges for leviathan giving you health (more) and if u catch 20 you will be unbeatable (hp, Armor&MagicResist +19%dmg reduction)

Remember a thing, a tank is somebody able to take large damage mitigating it or having a lot oh hp. that means less offensive items and why will somebody atack a tank that isnt a threat for him or his team? with bloodrazors u will do several dmg (u got nice ASpeed even being tank) and frozen malet helps too. then enemys should want to atack you instead of see how you move between them hurting them and disrupting with bear stance and freeze from the hammer, but if they dont pay atention to you, take another offensive item. If you can absorb too much dmg but doesnt any, enemys will atack your mates instead of you, so you will be failing as tank

It's time to talk about udyr's skills. You are clever so you know what does each one, that's why I will only tell you how to use (at least how I use):
: It's important in the begining, while you are farming in the jungle, to use stances before u lose the buff charges. specially at lvl 2-3 begin with phoenix, use turtle near to the buff lose but dont wait so much to change to phoenix again. That's just my way to jungle, you can try your own way. In fights you will use so much skills that is complicated that you lose the charges. Late game when you have enough mana you can use bear-turtle-bear all time to move faster even while not in fights.
: Tiger stance is used to do burst dmg (real burst and real amount). In early game while farming if you are using the dps skill secuence after lvl 4 use tiger-phoenix to farm if you are full health or tiger-turtle if u want to recover health. In ganks you will use bear (and ghost+youmuu) to catch your enemy the faster you can, then, change to tiger to do burst dmg. My best combo for gank is this: bear-tiger-bear quickly while they dont see u, that will make you move faster (3 chargues on monkey's agility) to your enemy that dont waits you, hitting him while in bear. That stun and do the burst, and u are still able to change from bear to tiger, doing the burst 2 times (OUUUCH). If your opponent still alive, in late game you can change to phoenix after that combo, because the waves will hit the foe while he runs and the persistent bonus ASpeed from tiger stance will make you atack faster in phoenix stance while few seconds, granting that the powerfull hit every 3 atacks occur more times. Under this stance you destroy turrets very faster.
: that is the stance you will use combinated with tiger/phoenix to farm during the jungle phase. The shield it makes can save your *** lot of times during a desperate flight (ghost+youmuu+bear-turtle-bear). It scales with AP so there is a point mid-late game where it use is less efective because yo dont use AP items (you use them sometimes in TANK build, as I explained before). You will use it too after a teamfight when your team win and go push, to heal yourself atacking minions (use tiger before to improve your atack speed before use turtle) and in TANK mode if the other team is focusing you (using bear-turtle-bear turtle to disrupt them and shield yourself).
: you will love that stance. You must initiate all your fights (I dont mean teamfights) under that stance to stun your target, then use tiger (using the combo I explained in the tiger stance description) if you are dps. If you are tank, bear-turtle-bear if the other team focus you, otherwise bear-phoenix-bear to do more aoe dmg while u stun each dps or chanelling champion or bear-tiger-phoenix-bear if you are focusing one of them (that happens when there are only many champions of them alive and you have to focus the more dangerous or just want to end somebody with low hp). You MUST REMEMBER that you just can stun a single target once every 6 seconds so dont use bearstance vs a target you know you have stuned low period of time ago.
: and finally phoenix stance, the stance you will use to farm in jungle (lvl 1-4 with dps build and whole game with tank build). It gives you bonus ap so your turtle stance will build a stronger shield if you were in phoenix stance before. TANK udyr use it to make AoE dmg while the other team dont focus him while DPS udyr just will use it after tiger stance at lvl 18 after the combo bear-tiger-bear-tiger-PHOENIX to optimize dmg or in rare times like fighting 1v1 vs a tank with thorn mail or while blind (to use tiger when blind dissipates).

I think that's all

That's the question that everybody knows its answer.
: we will depend of it to farm right, killing the golem lvl 1 and dragon lvl 3, quick defeat the dragon (the hard dragon)... we would be lost without it. It's sad but we depend on it. If you will choose a summoner spell different to that two (what i don't recomend) change it for ghost, never for smite.
: ghost, we can gank and scape nicely with ghost. It hasn't too much cd like flash (somebody will prefer it to scape through walls or instant appears in front of the enemy to stun with bear stance but I will still prefer ghost)
: I would choose cleanse if I will be tank, to make my annoyin bear stance not to stop.
: I don't recomend id but it's obvious that its usefull on ganks using on target you stunned or using on target that is few far to catch with bear stance even with speed buff.

That's the last I will say to you and its not refered to what can you do for your team, because I've been talking about it all the time. I will talk about when I would pick udyr (I usually pick him more than 50% but it is because I'm in love with him [by now] and love to play with that ****in hard boy [HE DOESN'T USE WEAPONS!!]). DPS Udyr works nice with tank+support+2 AP DPS, we could be talking that the team is udyr, shen, kayle, veigar, katarina. If we talk about TANK Udyr I would want an offtank, 1 ADdps and 2APdps like Udyr, nunu, fiddlesticks, tryndamere and akali.

I'm raving seriously xD, not rly, I'm just talking how my experience with Udyr is, and the types of matches I use to win and how.

Thanks to readers to read this large guide, it's my first one.
Thanks to the previous udyr guide posters, I realy learnt lot of things from them builts (at least from most of them), so I just had to play, live my experiences as Udyr and give you my personal point of view and small contribution to their done work.
Thanks to xumy "por ser como es".
I hope you enjoy playing that character as much as I do

AND PLZ IF YOU FIND IN A MATCH A DUDE THAT SAYS UDYR IS A BAD USELESS CHAMP CHOOSE IT AND DEMONSTRATE IT'S NOT LIKE THAT (im tired of noobs and people that tryed to use it and couldn't)