Kirby is the main protagonist of the franchise of the same name. He has the ability to inhale his enemies and gain their powers. He first appeared in Kirby's Dream Land in 1992, and is one of Nintendo's most famous characters.
Inhaling Kirby

Kirby inhaling

Kirby Jumping Into Spikes

Kirby jumping into a spike line after inhaling the player

Giant Kirby

A giant Kirby chasing the player

He also appears in I Wanna Be the Boshy as an obstacle in World 2, and as an unlockable character in the same world.

How hazardous is he? Edit

It depends on where in particular the player encounters him. He appears twice in the world. The first time, he tries to inhale you, and will jump when the player jumps. If the player is inhaled, Kirby will jump into the Spike pit behind him, killing the player. The second time, he has grown to an enormous size, making him too big to jump over. Walk back to the previous room and wait for him to pass by.