Hello everyone! This guide focuses on Itemization and Runes and won't be too in-depth but I'm an Udyr One Trick with around 800k Mastery Points across multiple accounts with my peak rank at Plat 1
This build is to help others from Iron to Plat as the aggressiveness of this build and playstyle wouldn't be efficient in higher elos.

Pros:
- Flexible and fun adaptive playstyle.
- Strong in every phase of the game early, mid and late and doesn't fall off depending on your build.
- Great objective control and rotation potential.
- Insane clear speed.
- Great dueling potential especially with Tiger Stance.
- Fast as hell, Bear Stance offers him a lot of movement speed.
- Great scaling shield with Turtle Stance, allows him to be a tanky champion.
- Has VERY high sustain.
- Easy to pick up, hard to effectively master.
- Split Push King Kappa.


Cons:
- Ganking can be hard due to having to rely on Movement Speed with no gapcloser.
- Udyr has no escape or dash thus being easily kited.
- Requires good positioning in teamfights in order to not be locked down.
- Mana problems for inexperienced Udyr players.
- Feast or Famine when using Trinity Force in your build.
- Has no ranged waveclear thus being weak for defending enemy sieges.
- When is this champion getting a Visual Rework.

Blue Side
Default Clear:
Red -> Wolves -> Blue -> Gromp / Scuttle -> invade enemy red
(Once you finish Blue you can skip Gromp to head straight to the enemies Red buff and then contest Scuttle)
Aggressive Clear:
Blue -> Gromp -> Wolves / Enemy Red Buff -> Gank or Scuttle

Red Side:
Blue -> Gromp -> Wolves -> Red -> Enemy Red Buff or Scuttle
(If you optimize your clear you can finish your red buff and make it to the enemy Jungler before or during his blue clear)

Although being very versatile with items, there are a few key items you'd want to build on Udyr.

Damage Items
- Warrior/Bloodrazor Enchant: Warrior increases Udyr's DoT damage and burst damage
though Bloodrazor gives the attack speed Udyr wants without the extra damage, pick these along with red/blue smite for the enemy team.
- Trinity Force: Udyr's Bread and Butter, gives you Attack Speed, Attack Damage, CDR, and Health, everything about this item suits everything an Udyr needs.
- Sterak's Gage: High base AD, Tenacity, and HP, very standard on Udyr but you can skip it for other tank items if needed/behind.
- Wit's End: Superior item compared to Guinsoo's Rageblade after the nerf, I usually get this item whenever I have a chance to as it suits my healing Bloodrazor build, Attack Speed and Magic Resist PogChamp?
- Ravenous/Titanic Hydra: Although I rarely purchase Tiamat as it delays the Triforce power spike, buying it when behind or you'd want to split push then by all means get this item and transition into Ravenous or Titanic.

Defense Items
- Randuin's Omen: Take this if you're being shafted by enemy Crit champions, the slow from it's passive comes in handy too.
- Dead Man's Plate: Not much to say about this item, gives you HP and Armor but most importantly BIG movement speed which is what this champion needs from lack of gap closers.
- Spirit Visage: The standard MR item for Udyr which compliments his W quite nicely.
- Thornmail: Everyone in Plat and below don't know what Heal Reduction is, so do yourself and your team a favor and pick this item up if the enemy has insane healing ty.