“General Kai. Supreme Warlord of all China! The Jade Slayer. Master of Pain. You may know me as the Beast of Vengeance. Uh... Maker of Widows? Okay, I used to work with Oogway?”
―Kai in the mortal realm
Kai the Collector is the main antagonist of DreamWorks Animation's 2016 animated feature film Kung Fu Panda 3. He is a supernatural bull who was the former brother-in-arms of Master Oogway and later, (upon his return to the mortal realm), he becomes a powerful evil Spirit Warrior. Thus, he can steal chi from Kung Fu warriors and turn them into Jade Zombies (or Jombies, as Monkey and Po call them). His scheme is to defeat every Kung Fu master and become all powerful.
Kai was voiced by J.K. Simmons, who also starred in Sam Raimi's Spider-Man trilogy as J. Jonah Jameson, Lionsgate's 2016 musical, La La Land, and voiced Yellow for M&M's commercials, Mayor Lionheart from Disney's 2016 animated film, Zootopia and later Detective Putty from Disney's 2022 live-action/animated comedy, Chip 'n Dale: Rescue Rangers.