Sonic earned his nickname by running really, really fast, just like his buddy Tails earned his name by having two tails, and Dr. Robotnik earned a PhD in robotics and a nickname to boot, but how did SEGA settle on a hedgehog as the main character instead of a rabbit, armadillo or a chicken wearing overalls?
And as for Dr. Robotnik, did you know he was initially going to be the star of the game? The original concept design for the character looked like Teddy Roosevelt, which SEGA felt would be a great way to appeal to Americans:
Okay, now I really want to see a Dr. Robotnik in Dreamland game!
Read Gamma Squad's Fifteen Fascinating Facts You Probably Don't Know About Sonic The Hedgehog