Bunby Heli

The Blader (called "Bunbi Heri" in Japan) is a helicopter robot that will follow and fly into its target repeatedly. In Mega Man 1, they come in green and blue. In Mega Man 4, miniature bladers emerge from pits to try to knock you into them if you try to cross without defeating them first. In Mega Man 7, Mega Man 8, and Mega Man and Bass, they get robotic bodies, thus becoming Bunbi Tanks.