From Sonic Retro
Dokabuton is a variety of badnik created by Dr. Ivo "Eggman" Robotnik, encountered by Sonic and Tails in Gigalopolis Zone during Sonic the Hedgehog 2 (8-bit). Resembling large robotic stag beetles, Dokabuton models have no proactive offense; they simply drive back and forth, damaging Sonic if he bumps into them. Dokabutons are easily dispatched by a spin attack.
Like other robots in 8-bit Sonic games, no animal friends pop out of Dokabutons 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.