Goof: If the chaos emerald of immortality makes one invulnerable to being hurt as well, wouldn't Robotnik go after that one first, instead of getting the invincibility one first?
Robotnik: (Laughing) I'm immortal! I'll live forever!
Robotnikhotep: Phew! thanks for making me mortal again.
Robotnik: But why would You want to be mortal?
Robotnikhotep: Are you kidding? Who wants to be chased by a crazy hedgehog for a zillion, zillion years? (Turns to dust.)
Robotnik: In that case, I'll just have to get rid of Sonic.