Jack the Knife
Jack the Knife is an enemy encountered in the game Wario: Master of Disguise. Its name is a pun of "jackknife," a type of knife, and the {https://en.wikipedia.org/wiki/Bobby_Darin Bobby Darin} song {https://en.wikipedia.org/wiki/Mack_the_Knife#Popular_song Mack the Knife}. It is a giant knife about the size of Wario, with eyes and "teeth"; It jump out of a table of the S.S. Caviar and tries to attack Wario. It is supposedly formed from the rage of a lifetime's worth of butter-spreading and other mundane uses for knives, according to the in-game description. Only one appears in the game.
In-game description
These dull and rusted knives are fueled by their own rage over a lifetime of butter-spreading and chicken kiev-slicing. Rusted and dull, they know neither remorse nor pity.