Snitch

From Hpwiki

The Snitch is golden and small enough to fit in a hand. It moves and hides at will. Catching the Snitch is the job of the Seeker; once it is caught, the game ends immediately, and the team who caught the snitch is awarded 150 points.

The snitch was created in order to prevent the extinction of the Snidget, the tiny golden-coloured bird originally used in games of Quidditch.