Dimentio

Dimentio is a malevolent, psychopathic jester who sought to use the Dark Prognisticus to end all worlds. However, he was stopped by Mario, Luigi, Princess Peach, and Bowser. Following his defeat, he became aimless and drifted through the dimensions.

He is the reason Interdimensional Black Ops was created, and has spent a portion of the time since his defeat running from them.

Trivia

 * Dimentio's name is a pun on the words "Dimension" and "Dimentia"