Tree Crawler

Throughout Sonic Chaos, and in a marked change of his tactics from other early games, our old friend Doctor Robotnik apparently thinks he's too important to face Sonic or Tails personally (until the last boss). Instead the Doctor deploys larger, tougher, nastier badniks as boss robots. Mecha Green Hill Zone's boss is some kind of trunk-hugging armoured... beetle-sloth-monkey-thing. While shimmying up and down a robotic palm, the machine spits out energy bolts from a cannon hidden inside its back. Not nearly as problematic as its Sleeping Egg predecessor, the boss can be defeated through the standard tactic of 'dodge the attacks and jump on its head'.

Incidentally, the boss' Japanese name, Kamado Max, derives from the Japanese word kamadome, meaning "Do not cut the trees".