Tsuno-tsuno

Tsuno-tsuno is a variety of badnik created by Dr. Ivo "Eggman" Robotnik, encountered by Sonic and Tails in Sleeping Egg Zone during Sonic Chaos. Quite what these weird, vaguely onion-shaped machines are supposed to be isn't known, but Tsuno-tsuno models have no proactive offense; they simply drive inexorably forward, jumping occasionally and damaging Sonic if he bumps into them. Tsuno-tsunos are easily dispatched by a spin attack. Like other robots in 8-bit Sonic games, no animal friends pop out of Tsuno-tsunos when they are destroyed. Whether these badniks canonically don't contain organic batteries, or the escaping critters simply weren't shown due to programming limitations, is not known.