Homing Chomp

Silver Chomps are a new type of Chomp in Super Mario Galaxy 2. They resemble giant silver Chomps with yellow irises and red pupils. Unlike other Chomps, Silver Chomps will always roll towards Mario and try to hit him.

A single Silver Chomp first appears in the Rolling Masterpiece Galaxy in the mission Silver Chomp Grudge Match. One later appears in the Slipsand Galaxy, in the mission Sailing the Sandy Seas. A total of four Silver Chomps later appear in the Battle Belt Galaxy on the final planet in Mini-Planet Mega-Run and Mini-Planet Daredevil Run.

These enemies can only be defeated by Rainbow Mario, by pushing them off a cliff while on a Star Ball, or by the use of a Stretch Plant.

Trivia

 * An extremely large Silver Chomp appeared in the E3 2009 trailer of Super Mario Galaxy 2, though it never made it into the final game. In the trailer, it seemed to be acting similar to Sorbetti during the boss battle in the Freezy Flake Galaxy, so it is possible that this Silver Chomp was originally intended to be a boss, but was replaced by Sorbetti in the final version of the game. The game designers may have decided to compensate for this by downgrading the Silver Chomp to a lesser enemy instead, and incorporating it into several levels nevertheless.