'Sonic The Hedgehog' And Fan Service The new movie Sonic the Hedgehog is about this hedgehog — who runs fast. Ben Schwartz voices the Hedgehog, Jim Carrey is the evil Dr. Robotnik, and James Marsden is also in there somewhere. When the film's trailer first dropped last fall, Sonic's appearance — the legs! the teeth! — creeped a lot of people out. The studio went back and redesigned the character completely, which got us thinking about the power of fan reaction.