Mickey Mouse
In matters of raw speed, the mouse must be evaluated on metaphorical rather than literal grounds. Mickey has never claimed supersonic capabilities; indeed, his locomotion appears limited to a cheerful trot. However, one might argue that the speed at which Disney properties have colonised global entertainment represents a form of corporate velocity unmatched in entertainment history. The acquisition of Marvel, Lucasfilm, and 21st Century Fox occurred with breathtaking swiftness, suggesting that Mickey's empire moves faster than any hedgehog could sprint.
Sonic
The hedgehog's entire raison d'etre centres upon velocity. Documented speeds exceed Mach 1, with some accounts suggesting capabilities approaching light speed. This creature transformed speed itself into a personality trait, a philosophy, and a brand identity. The very name Sonic derives from the sound barrier the creature routinely shatters. In pure kinetic terms, the hedgehog represents perhaps the fastest entity ever conceived in animated fiction, capable of running on water, up vertical surfaces, and through the fabric of spacetime itself.