Intro
So this is my second attempt at an Udyr guide, after reading through all the comments on my last guide. Let me start off by saying that this is not a 
Tiger Stance guide, or a 
Phoenix Stance Guide, but rather a mix between the two stances for maximum late game damage output. Udyr is an excellent jungler, but i prefer to lane with him do to his massive early game single target damage output with Tiger Stance. I do focus more on Tiger Stance early game so you can hopefully wrack up some champion kills early game, as this build is extremely expensive. This guide will work for 3v3's or 5v5's, but it was designed for 5v5's in mind.
Summoner Spells
While 
Ghost is an excellent summoner spell for Udyr, i prefer not to use it because the slow provided by 
Hextech Gunblade and 
Bear Stance speed boost and stun are more than enough for me to catch up to and kill enemy champions
I prefer to take 
Exhaust instead because it allows you to catch up even faster to champions and severely reduces the damage that enemy champions will deal to you. I find this to be more valuable than ghost, because while you deal massive amounts of damage, you are very squishy early game
Ignite allows you to quickly kill enemies with lots of life steal or heal, deal the finishing blow to a fleeing enemy, or turn the tide in a close battle, especially when coupled with the DOT from Tiger Stance
Flash is a valid option as well, however you have pretty high base movement speed and generally don't need an extra escape mechanism because Bear Stance is sufficient, however if you are really good with flash or like its versatility then take it instead of exhaust, but make sure you keep ignite for the extra damage
There are other spells that work with Udyr, but these are the best ones in my opinion, however feel free to experiment and comment on what you think
Masteries
i use a fairly straight forward 21/9/0 build for Udyr, grabbing improved exhaust and ignite in offense. the 10 bonus AP from the ignite mastery is a lot better in my opinion than the 3 extra damage, because you also have enough points to max the attack speed buff as well. keep in mind this build is made for late game dominance and 1 or 3 attack damage will not make any difference then, but 4% attack speed will. i take magic resist over armor as Udyr has very high base armor compared to most other champions but is lacking magic resist. the nimbleness mastery is almost required on Udyr because of his passive, and it will allow you to escape easier or chase down an enemy faster if you are running through their minions
Early Game
Start out with 
Doran's Blade and Tiger Stance, and prepare to get first blood. If the enemy team has a lot of CC you can rush your mercury treads, but doran's blade is an amazing starting item. you can easily out damage anyone else in the game at level 1, so don't be afraid to charge in, just don't be suicidal about it unless you know you can kill them first for First Blood. Even then, i would advise you to take your time and get a kill without sacrificing yourself, as the 100 extra gold you get is no where as good as getting 300 total gold and giving the enemy nothing. Exhaust should give you enough time to burst down most of your opponents HP with tiger stance, and Ignite will stop them from healing and most likely ensure a kill. remember to last hit as much as possible, and don't be afraid to jungle if you start to fall behind or need some extra money. once you hit level 5 or so take blue buff if you don't have a jungler, as Udyr has extreme mana problems early game, but these become virtually non-existent by level 18. Feel free to get it earlier if you have a teammate willing to help, but level 5 will allow you to kill it without loosing too much hp so you don't have to be afraid of getting ganked while getting it. The cooldown reduction provided by the buff is also amazing on Udyr, making it almost impossible for him to loose a 1v1 because he can endlessly spam his stances without worrying too much about mana. always open up on enemies with your stun, then immediately switch to tiger stance so you can deal the most damage before they start running. If they decide to stay and fight, keep spamming tiger stance whenever it is available, then use turtle stance if the enemy is doing too much damage. throw phoenix stance into the mix while tiger is on cooldown to deal even more damage, but be careful about your mana as phoenix takes a lot of mana early game. Chase the enemy with bear stance if you think you can get the kill, but i would not recommend turret diving yet as you are still fairly squishy
Mid game
By this point you should have your Hextech Gunblade, which is one of my favorite items. the stats are wonderful, but what is truly amazing is that it can slow an enemy by 50% for 3 seconds, which is one of the more powerful slows in the game (not quite 
Nasus level though). It also deals 300 damage, so use it to peck off that fleeing enemy before they can get away if you haven't used it already. The slow allows you to quickly and safely close the gap on ranged champions and prevents them from being able to kite you. once you get close enough to stun an enemy champion just use the same strategy described in the early game section. your 
Sheen will increase your mana pool significantly, as well as massively increase your damage output, as it can activate almost every time you change stances. try to time your stances to maximize sheen procs, as this becomes an even more useful skill once it is upgraded into a 
Trinity Force. by the time you get your trinity force the entire enemy team should likely be running from you on site, but no matter, your movement speed and gunblade should be more than enough to close the gap. The enemy will likely be running to a bush full of 4 more enemies, so watch out for ganks, as map awareness is key on Udyr. Udyr is also one of the best gankers in the game, so if an enemy is over extended go there and teach him a lesson. with a decent amount of kills it is possible to finish your gunblade and trinity force 20-25 min into the game, so aim for that if possible.
Late Game
This is were Udyr really stands above the rest, so abuse your abilities to their fullest. At level 18 you can basically run around the map and kill lone enemy champions at will, just be sure you know where the rest of the enemy team is as they will likely be trying to bait you. 2 enemy champions should be no problem for you, so jump right in and spam your stances away. It is possible to 1v3, but you have to be sure to kill one of the enemies as quickly as possible, because while Udyr can soak up more damage than most with his shield, he will die extremely fast if he is focused for too long. If you do attempt to 1v3, try to focus on the squishiest champion while exhausting the one that does the most damage, essentially eliminating two of the 3 champions damage as quickly as possible. if the fight isn't going your were, bear stance and turtle away, as its better to give the enemy no kills then trade 1 for 1. if you find your self low on health, phoenix stance into a large group of enemy minions, and watch as your spell vamp does its work. keep triggering phoenix stance as long as lots of minions are around, and switch to turtle when there are fewer targets. it is possible to solo baron at max build, but its time consuming so get your teammates to help you if they can, or at the very least distract the enemy. Udyr also makes an excellent ward hunter, so grab an oracle and roam the jungle. if you are lucky, the oracle will pay for itself, just be careful not to die. Also don't forget that after a trinity force all items are situational, the build i gave will do the most damage, but get tankier items if you find yourself dying too much, or if the enemy nukers are killing you before you can do anything. armor and magic resist are always a good choice as the damage modifiers apply to your turtle shield as well.
Final comments
Thank you very much for reading my guide and i hope it serves you well. if you have any questions or comments feel free to add me on League of Legends. My in game name is b2dude. Please comment and share your thoughts on how i can improve this guide as it is till a work in progress. Also, I would greatly appreciate it if you try it out in a game before voting down the guide simply because it is a lane Udyr guide and not a jungle Udyr guide. There are plenty of jungle guides around, I wanted to try something different, so here it is. Enjoy.
Build Guide
Discussion (6)
Greater Seal of Evasion stacks with your passive and nimbleness in order for you to make quick escapes and stand up better against high physical damage champions like 
Master Yi
Greater Glyph of Cooldown Reduction allows you to activate your stances quicker and keep up your passive at maximum stacks easier. 11% cdr will allow you to use only one stance to keep your passive from resetting. the 6% these provide along with your masteries and Golem buff with allow you to break the 33% barrier which will let you constantly get the movement speed boost from bear stance
Greater Quintessence of Magic Resist will increase your magic by 13.5 which will make it harder for mages to focus you down in team fights. you can also take 
Greater Quintessence of Health which will give you 76 extra health. This will help you out very much at the start but is practically useless late game. greater quintessence of desolation will give you 10 extra armor penn, giving you 31 total armor penn at the start of the game, which will probably be more then your opponents total armor, allowing you to deal more damage than you actually have, which is very nice. these remain effective all game, and in fact become more effective as the game progresses because they increase the damage you do to enemy champions by a percentage, not a flat amount. Quintessences are fairly interchangeable, but i would not recommend messing with the other runes unless you know what you are doing.
