Looks like the Oddball

Looks like the Oddball is an achievement in Halo: Combat Evolved Anniversary. It is awarded for finding and claiming one campaign skull. It is represented by a human skull over a red five-pointed star.

The Achievement is worth 10 Gamerpoints.

Trivia
The name of the achievement is a reference to the fact that campaign skulls are similar in appearance to Oddballs in Halo multiplayer.