Cosmic Comet

A Cosmic Comet is a type of Prankster Comet in Super Mario Galaxy. It involves a race with Cosmic Mario or Cosmic Luigi, depending on which character the Player is controlling. At the end of the race, there is a Power Star. If the Cosmic version of Mario or Luigi gets to the Power Star first, you lose a life, and have the option to start again, or return to the Comet Observatory. It is unknown if Cosmic Mario and Cosmic Luigi are related in any way.