Ripper Roo (Earth-6515)

"You are crazier than me! Have a key. Good luck, you'll need it!"

- Ripper Roo

Ripper Roo is an insane genetically altered blue Mutant kangaroo created by Doctor Neo Cortex, whom he widely considers to be his first and failed experiment with the Evolvo-Ray before moving in to create Sonic Hedgehog. He frequently uses explosive crates when fighting against Sonic.