Hello! My name is Ruckus, and I'm starting off on MOBAfire with my first Champion build. Please feel free to leave feedback and tell me about any revisions I should make! This build is focused highly around shredding armor to pieces and tearing champions to ribbons with Udyr's infamous Tiger Stance. AD Udyr is mostly used for when your team already has a tank, or when you want to be extremely aggressive in lane.

Pros
+ Does massive damage throughout the game
+ Easy to chase with
+ Easy to escape with
+ Good at split pushing
+ Great sustain in lane with Turtle Stance
+ Free stuns with Bear Stance

Cons
- Not nearly as tanky as a hybrid/full tank Udyr
- Phoenix stance is useless early
- Udyr has no real 'ultimate'
- PETA will be after you constantly

If you're planning on going AD Udyr, Tiger Stance will be your best friend, so you should plan on maxing that out first, as it is your main damage dealer. Second, you can max either Turtle Stance or Bear Stance. Turtle Stance is better for the sustain and shield, but if you feel like you aren't catching up to your enemies quick enough, go with Bear Stance for the extra duration on your movespeed buff and removed unit collision. After that, use your last three spare points on Phoenix Stance, because you have nothing else to use them on.

Monkey's Agility -
Udyr's passive is a key part in dealing much more DPS due to his constant switching of stances during battle. The more you switch, the more attack speed/movement speed you get, and the more attack speed you get, the more DPS you dish out. The more you switch, you get more movement speed as well, which helps you in sticking to your enemies and running away from them as well.
Tiger Stance -
For this build, Tiger Stance is going to be your bread and butter. It's your main harass in lane and your main damage dealer throughout the game. It increases your attack speed, which Udyr gains simply by pressing Q, and it stacks with his passive which also grants a nice bit of attack speed to continue shredding people. The DoT effect he gets from the passive portion of the stance is also very nice to harass your lane opponent and helps to secure last hits to make sure you get every CS you go for.
Turtle Stance -
Your lovely sustain ability. Gives you loads of lifesteal when you are currently using the stance and gives you a small shield so you can soak up some damage while trying to extend a bit further for a last hit or to take some minion hits to get some health back.
Bear Stance -
Your built-in stun. You can't use it repeatedly on the same target more than once every 6 seconds, but it's still a free one second stun with a small dash to make sure you can hit them with it. It's very helpful to use the Active which increases your movespeed and removes unit collision to chase an enemy down or to run away from incoming pursuers. A good strategy when getting dived on is to stun the enemy, hit them once with Tiger Stance, then run away as they get killed by the turret. Usually, even if you die, you'll secure at least one kill for yourself in death.
Phoenix Stance -
Overall not a terrible ability, but it has no use to us early in the game. Use your last 3 points on it, because honestly, you won't be using it nearly as much as the other stances.

Ignite
A good choice if you really want to do tons of damage over time. Combined with your Tiger Stance's passive, their health will quickly melt.

Flash
A very common choice among all summoners, Flash is arguably one of the best summoner spells in the game. It helps to escape, to initiate, and to hop through walls to surprise gank some unsuspecting enemies.

Exhaust
Why Exhaust? It helps you to duel any champion in the game by reducing their damage, movespeed, attack speed, and overall usefulness in general during a fight. It has multiple uses in lane and out of lane, such as escaping, chasing, disabling, etc.

Teleport
A long-time favorite, Teleport never ceases to be awesome. It can help prevent a successful split push, it can cause a successful split push, it can be used to surprise gank somebody, and it can be used to get in on a teamfight if you managed to get in late.

Cleanse
It's a very situational summoner spell, but AD Udyr can easily be tied down by CC, so this is probably a helpful choice if the enemy team looks like they just arrived home from a CC convention.

Ghost
If you REALLY hate people escaping from you, run with Ghost. Even though you have Youmuu's Ghostblade and Bear Stance, if you REALLY need to get your gears in action, bring along Ghost for that extra burst of speed.

Smite
If you're jungling, take it. If you aren't, don't.

Clairvoyance
Not many people use Clairvoyance and I find it to be a waste of a summoner spell, especially if you're not a support.

Heal
It isn't really necessary, as you already have Turtle Stance to heal yourself with, and the shield can prevent death by itself.

Clarity
You probably shouldn't run out of mana unless you go all in on somebody early game. Late game, mana shouldn't be a huge problem either.

Barrier
You already have a shield in your abilities, so a second one seems a bit unnecessary. If you really want to be a turtle, go ahead and take Barrier though.

In conclusion, Top AD Udyr is a very viable build which can be used if you are forced out of the jungle or your team already has a tank or you don't want to build tanky. As my first build, I'll be happy to see feedback coming soon. I hope to make more builds in the future and improve over time. Hope you enjoyed!