Bonk was Hudson Soft's video game character meant to rival Mario and Sonic. He debuted in Bonk's Adventure (1989, PC Engine / TurboGrafx-16). Known as PC Genjin in Japan (a pun on "PC Engine" and genjin, meaning caveman) and B.C. Kid in Europe.

He's a bald prehistoric infant with a comically oversized skull that doubles as his weapon. He attacks by headbutting, dive-bombing skull-first, and biting surfaces to climb. King Drool, a tyrannical dinosaur, kidnaps Princess Za of Moonland, and Bonk crosses the prehistoric world to rescue her.

His signature mechanic is meat. Small chunks put him in a temporary rage where he's invincible and enemies flee; large meat turns his face bright red and lets him stun everything by stomping. A great mechanic to steal: a consumable that visibly transforms the sprite.

Sequels included Bonk's Revenge, Bonk 3, Super Bonk on SNES, and Air Zonk starring a cyborg descendant. A revival, Bonk: Brink of Extinction, was announced around 2010 and cancelled.