Emblem

Emblems are items that are mostly in Sonic Adventure, Sonic Adventure 2, and Sonic Heroes that are gained after completing a stage, or completing certain requirements or missions.

Description
Emblems resemble giant rings with wings. Sonic is usually seen in an emblem performing a pose. They bare resemblence to the title screens of early Sonic games for Mega Drive.

Purpose
Collecting emblems usually unlocks secret content such as mini games and Metal Sonic in Sonic Adventure, Green Hill Zone in Sonic Adventure 2, and Super Hard Mode in Sonic Heroes.