6. Dr. Robotnik/Eggman (Sonic the Hedgehog franchise)
This guy’s been bugging Sonic since the very beginning, turning furry critters into robots and building giant mechanized monsters in order to… rule the world? Destroy one hedgehog? (His motivations aren’t always completely clear.) Considering that the Smash Bros. series has a dearth of truly villainous characters as it is and the fact that Robotnik’s robotic antics would make for a pretty diverse moveset, throwing the egg-shaped mad scientist into the arena seems like a no-brainer. Bonus points if you actually call him Dr. Robotnik and not the more modern Eggman – sure, the latter’s more in line with the original Japanese, but to a generation of Sega Genesis players and Saturday morning cartoon watchers, it’ll always be the former.