Just to say, this is my first guide, so please dont rack to much on me.

This is an AD Udyr build, your main dmg will be the dot on Tiger Stance activation, but this is only in the beginning of the match, later, if everything went as planned, you will just be a AD wrecking machine with unmatchable running speed thx to Trinity Force, Bear Stance activation and Ghost.

The runes are very standard for meele dps, AmP on Marks is just all around good for meele dps, at the end with both The Black Cleaver and Bloodrazor/Last Whisper you will wreck even Dr. Mundo(this is just becuse i really hate Dr. Mundo) becuse your AmP will be so high. HP on Seals is nice to have as meele, and since 0 of your items is defensive, you kinda need HP on Seals and Quintessences. The MR on Glyphs, i use this on all meeles, almost all atleast, and again you aint gonna be using any defensive items so you need it.
Masteries, these are also all out offensive. You get all the major dmg increases in offense, and you get the amzing exp boost in utility. Thats pretty much all there is too it.
And items, having Bloodrazor in early game is very nice, becuse then you can kill dragon the minute it spawns if you solo laned, which you should be doing. but later on you change it to Last Whisper, becuse with all the AD its much better to have 40% AmP, Trinity Force is the best thing in this build, becuse if you have gotten to it, your Tiger Stance and Sheen procs will deal an absurd amount of dmg. It also gives you that little exstra Attack speed and Move speed you need to really do ****loads of dmg. And you can also exchange Bloodrazor for LAst Whisper later if you playing against some hard armor tanks, Rammus, Dr. Mundo and also Galio cuse he has ****loads of MR.

For summoner spells i take Ghost and Flash.

Ghost, becuse it makes ganks really easy with Bear Stance activation, and also it makes escaping really easy.

Flash, becuse on pretty much on every champ in 3s i use flash, just becuse you can get out of almost any situation with flash in 3s. And for Udyr espeacielly, its very usefull for early ganks.

Some of the other spells can also work really well with Udyr Tiger build.

Exchaust, Udyr doesnt have a slow on his own, and even tho he gets one from Trinity Force, this is still surperb, this can also help with the fact that he is build with no defensive items in this build.

Ignite, this can help you alot in early game, but i only think this ability should be used if noone else on your team has it.

Heal, Teleport and Cleanse can be ok, but i only think these four spells are good for Udyr in 3s.

Abilitys.

I go for Bear Stance first, mostly, but not always, depends on whether my teams goes first blood or not. I not i go Tiger Stance first. And then i follow the pattern i describe above for max Dmg and mobility, and since i wont be using Pheonix Stance ever there is no point of taking it. And the one point in Turtle Stance early is for the Life/Mana steal, and the shield if needed ofc, but mainly for the steal effects.

That was it, i would go into some more strategy, but i dont have a good recording program, and writing strategy doesnt work so smooth, but i hope this guide helped you abit, atleast about how you should build Udyr, and please keep in mind, this is the first guide i have ever made so, just ty for reading all the way down, plz vote and comment.