Nitron

Nebula (ニトロン) is a flying eye-like enemy in Mega Man 3. It is in the first section of Gemini Man's stage (the surface of the space glacier), both regular and Doc Robot. When Mega Man is close, it swoops down and drops three fireballs that spout into small flame geysers, a little bit like what Flame Blast does later on in Mega Man 6.