- He is the only character that cannot max out all of his skills, as each of his skills have five levels and the max character level is 18 (18 points for a total of 20 possible ranks).
- However, in the Ultra Rapid Fire (2015) featured mode, there is not the limit of champion's level, so Udyr is able to have 5 levels for his abilities.
- He is one of the only characters without an ultimate along with Jayce. Udyr has 4 skills that can be leveled up to the maximum rank of 5.
- Udyr is one of a few champions to have multiple textures in one skin. Udyr however has more different textures in one skin than any other champion, as he has a different one for each of his stances.
- Udyr's dance shows the Drunken Master Kung Fu Style. A side-by-side comparison can be seen here.
- Udyr is one of two champions that went into the weekly champion rotation on the day of their release. The other one is Poppy.
- Udyr was one of the champions chosen for the Ionian pool available during the Ionia vs. Noxus match. He was one of the selected champions, and was voted the MVP.
- Udyr was designed by Steven 'Coronach' DeRose.
- He was the first Champion released after the official October 27, 2009 launch of the game.
- He is named after Steve 'Udyr' Mieczkowski. 
- Udyr is voiced by J.S. Gilbert.
- Udyr's original champion title was "the Animal Spirit" but with the Freljord patch his champion title was changed to "the Spirit Walker" and changes were also made to his lore.
- His name "Udyr" literally translates into 'Beast/ Monster' in Danish, Norwegian Bokmål, and Nynorsk (cognate with Swedish 'odjur' and German 'Untier'). Etymologically, 'udyr' comes from negative prefix 'u-' and 'dyr'. 'Dyr' is cognate with German 'Tier' and English 'deer,' meaning 'wild animal' (narrowing down to cervids in English). However, "udyr" is mostly used to describe people acting like animals and not caring if they kill. Hypothetical English cognate would be '**undeer.'
- Almost all of Udyr's skills are based off the , with the sole exception of the Azure Dragon.
- Udyr's joke "If Peta asks, this fur is fake" refers to the Animal Rights group and their notorious ways of getting the public to not wear fur.
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- May be inspired by Native American mythology.
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- The theme behind Udyr's Ultimate Spirit Guard skin is one of the possible outcomes for Runeterra. In this future, Udyr reaches inner harmony and conquers his rage during his time with the Ionian monks. He then guards the Hirana Monastery from demons and corrupt monsters that would use the Temples power for the destruction of Runeterra.
- This future may also depict a possible outcome for .
- His appearance and clothing style resembles that of Shaolin monks and guardian statues found in temples and shrines of Asian culture. They are often depicted in a meditative or defensive posture, featuring exposed torsos and wearing large over some body parts. Traditional footwear (like ) and waistcloth (similar to South-Asian garments like a Lungi) as well as bright glowing eyes without pupils are also recurring features seen among them.
- He also bears a striking resemblance to the Sura Master NPC from Ragnarok Online, if one doesn't count for the hairstyle.
- Spirit Guard Udyr's Level 5 Bear Stance has a similarity to the Street Fighter character , one of alternate forms. Both have bluish glowing skin and aura, a large prayer beads, bear-claw shaped hands, exposed upper bodies and gruffy hairstyle resembling flames.
- Using a Dance, Laugh, or Taunt emote command with Spirit Guard Udyr summons whichever spirit corresponds to his current stance. His Dance will summon all four spirits in sequence once any given ability has reached rank five. His Joke summons Warwick. , which finally explains where Urf's spirit went after being killed by
- This skin represents his state as a monk after finding his inner harmony and conquering his rage completely, even when fusing with one of the four spirits. This stands in strong contrast to his non-ultimate skins which represent his feral nature and somewhat still-uncontrolled rage.
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- He celebrates April Fools' Day 2015.
- His Recall animation is probably a reference to Usain Bolt's Signature "Lighting Bolt" Celebration Pose.
- He shares this theme with Blitzcrank, and Vel'Koz.