List of Sonic the Hedgehog characters

This is a complete list of characters who have appeared in Sonic the Hedgehog in order of appearance.

ART
One of Doctor Robotnik's most powerful creations, ART was developed for the purpose of defeating the Sonic Underground and their Freedom Fighter allies. Able to absorb any technology into his frame to increase in size and power, ART is a learning robot, capable of adapting to anything his opponents might deploy. "ART" stands for "Artificial Robot Technology".