Yadokargo

Yadokargo (ヤドカルゴ) is the boss of the opening stage in Mega Man 8, a crab-like robot that protects Dr. Wily's secret base, and accumulated moss on its shell due to the long time it stood still. He pinches at Mega Man, leaps, and shoots bombs. His weak point is his brain, which is protect by his shell. When hit by a charge shot or one Mega Ball, his brain is exposed. When visiting the stage again, he can be destroyed instantly with Astro Crush or Tornado Hold.

Trivia

 * His name is derived from "yadokari", Japanese for hermit crab.