Nowdays, Dr. Robotnik seems to create dull, generic looking robots. But back in the good old days, he basically took Sonic's Flicky friends and turned(or "Roboticized") them into animal-like robots with all sorts of features called,"Badniks". Whenever Sonic destroid a Badnik, it would also free one of his Flicky friends and they would jump out and be on their merry way.
Although they're still robots, the Badniks had more color and life-looking than the generic robots we see today. Plus these little buggers are just friggin' cute!>w< With their big boggly eyes, and all the animals they're based on! But thankfully they actually have started to make a comeback in games like Sonic 4 and Sonic Colors, so hopfully they can get back to being the main enemies in the games.
For this pic I just added classics like Motobug, Crabmeat, Buzzbomber, Catterkiller, Orbinaut, and Bat Brain. I hate the BG though.>.< I was trying to make it look like Scrap Brain Zone, but instead it looks like a cross between Scrap Brain and Spring Yard Zone.:P