Merserker (マーサーカー,Māsākā?) is an axe-like enemy from Mega Man 10 that inches towards enemies while stomping the ground, using a small rocket on its knob to hop and a rocket in its poll to move down and cut with its blade. It appears in Blade Man's stage. In Hard Mode, it moves a lot faster.
Merserker's name is probably derived from Masakari (鉞), a kind of battle-axe.