Sonic Team head and original Sonic the Hedgehog programmer, Yuji Naka, revealed in an interview recently that one of the original ideas for the speedy blue hedgehog was for him to be a rabbit.
When asked what the initial idea of Sonic was back in 1990, Naka explained that he liked the idea of a fast animal being the protagonist of the game. But, in order for a rabbit character to attack, the player would need to stop moving. This encouraged the Sonic Team at the time to look for another creature:
I wanted to create a character that would compete with [Nintendo Co.’s] Mario. At first, I liked the idea of a rabbit because it’s a speedy animal. I also considered the idea of having the character throw things with its ears. But I realized that in order to do that, the rabbit would need to stop running.
So I started to think of a character that can defeat enemies while moving at the same time, rolling and clashing against them. I hit upon the hedgehog. A hedgehog has spines on its back, so it can roll and clash against the enemies. So, the reason I chose a hedgehog as the main character of the game was not because I like hedgehogs but because of the necessity of the game.
Naka also speaks in the interview, conducted by LA Times, of the differences in tastes between American gamers and Japanese gamers, as well as the elements of what makes a long-lasting character like Sonic. Read more on the LA Times website here.