Veg-o-Bot, known as Tsuno-tsuno (ツノツノ) in Japan, is a variety of Badnik created by Dr. Eggman, 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 or Tails if they bump 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.