Nitron (ニトロン,Nitoron?) is a flying eye-like robot enemy in Mega Man 3 that used to melt hard rocks in energy resource mining areas. They appear in the first section of Gemini Man's stage, both regular and with 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.
In the Gemini Man Doc Robot stage, the color of the fire is blue and their body is yellow.