Hedgehog (EntityClass, 4)
From Compile Worlds
A hedgehog is a spiny mammal. However, SEGA is dead set against this definition, and have installed numerous laboratories dedicated to the research and creation of "fake" hedgehogs. Over the years, these beasts include:
Of these, the two that particularly love to argue about whether they are fake or not are Sonic and Shadow.
After creating Sonic, SEGA realized that Sonic would destroy the world, so they recruited the world's top scientist, Dr. Eggman, to stop him. However, it seems SEGA were dumb enough to continue producing hedgehogs (thus the list above), though none of the succeeding creations have had anywhere near as much effect as Sonic did.