The King puppet is one of the puppets in Vault 77 in Penny Arcade's One Man, and a Crate of Puppets comic.
Background
He became 'friends' with the Vault 77 Dweller. He was then 'killed' by the Vault Boy puppet when he chopped his head off.
Appearances
The King puppet appears only in the One Man, and a Crate of Puppets comic.