ART

One of Dr. 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 of Technology".

ART was sent to capture the Hedgehogs, going through several form changes as he attempted to abduct them. Despite managing to thwart him several times, the trio were caught by ART while rehearsing for a concert. However, ART had heard them play, and requested a song. The group obliged, and ART's free will was activated by the music, even leading him to play a keyboard similar to Sonia's.

ART then defected to the Freedom Fighters, using his impressive abilities to free prisoners and destroy SWATbots. However, he and the Hedgehogs were later caught in a crushing chamber. Using his strength, ART blasted a door so that his friends could escape, but he himself was crushed. However, he also served to inspire Manic the Hedgehog, who at that time had been feeling as though the efforts against Robotnik were pointless.