Farm until lvl4, get recurve bow, invade/gank as much as possible, udyr is one of the most op combaters/gankers in the current meta. After nashors/lichbane, you're basically unstoppable. Always look for drakes, you can solo it with only a recurve bow. Udyr has really great countergank potitential, use that advantage. Split as much as possible, since you have high clearspeed/towerdamage also your E/W gives you a great escape tool.

This is really important, flash your mastery as much as possible, after getting a kill/objective or dying. This is your mental strategy for tilting the enemy. When ganking (if the kill is 100% secured) stop for 1-2 seconds, start laughing/dancing/flash your mastery, just to show them dominance.

Udyr can be basically built to anything (tank/ad/ap/attackspeed/support/splitter/assasin etc.
The champ is literally so unbalanced, you can easily 1v9 every game, you just need a little bit practice, but after getting the hang of it, you should be able to climb with at least 65% winrate. Just follow my Build/setup and you'll smash those low elo scrubs for sure.
Dont be a *****, go in every single time possibly, this also shows your dominance just like flashing masteries. Udyr isnt meant to be played by some hardstuck kid with 9000 games/season, udyr is only for CHAD people. If you're a girl or a child, please leave this guide.

Wise words from a wise man:
Don't get me wrong, disrespecting is fun. But when i see low elo players consistently disrespecting i start thinking to myself, yo i would consider learning the game before you ****-talk and disrespect everyone