Mister Shifter

Mr. Shifter only appeared in one issue of Sonic The Comic, issue 87, where he was the main focus of the story Mister Shifter (the most important occurrence in this story was the revelation to Robotnik that Sonic was stuck in the Special Zone at the time). A shape changer from the Black Zone, made of "Radioactive Meta-Clay", he had the power to stretch like rubber or become hard as rock.

Shifter was either a robber or assassin, and was caught by Sonic trying to shoot a young Mobian girl (in fact a spy for Robotnik investigating if the Special Zone was ripe for invasion). Cocky and arrogant, Sonic managed to defeat him by literally stretching him to his limit, then letting him go.