Cosmic Clone

Cosmic Clones (or Shadow Clones) are shadowy duplicates of Mario or Luigi that appear in Super Mario Galaxy 2. Cosmic Clones are created once a certain point is reached in a galaxy and will follow behind Mario or Luigi, performing every movement the plumber makes. Once the way out of the area Mario is in is revealed, they will disappear, leaving behind a multiple of 3 Star Bits. If Mario touches a clone, he will take damage, so horizontal movement is necessary for survival. Boards usually warn the plumber that Cosmic Clones are present in the area. Cosmic Clones also are able to walk where there is no platform if it is necessary for following Mario. Also, Cosmic Clones will do whatever Mario did, even if the landscape has recently been changed.

The Cosmic Clones most likely replaced Cosmic Mario as Mario's cosmic entity.

Trivia

 * The Cosmic Clone's theme is a mix of the SMB overworld theme and the underground theme, like Cosmic Mario's from the prequel.