Cosmic Luigi

Cosmic Luigi is a character who appears in Super Mario Galaxy. He replaces Cosmic Mario when playing as Luigi and is very similar to him; the only major difference being that he takes advantage of shortcuts very often and uses a lot of Long Jumps, making him faster and much harder to beat than his counterpart.

In Super Mario Galaxy 2, despite not being in the game while playing as Luigi, Cosmic Clones behave very similarly, being slightly faster.