Rounder

'Rounder (ラウンダー) is a flying enemy in Mega Man 5, which basically looks like a flying eye. They appear in groups of three at the end of the first Proto Man/Dark Man stage (right before the boss gates). They don't really attack, just circle around Mega Man and interfere with his shots (which could be dangerous since it appears along with Search Mines that also appear near the end of said stage). 'Rounders can also crash into Mega Man if he jumps before they begin to circle completely, but cause little damage. They can be easily destroyed with the Mega Buster or Water Wave, but if ignored for a sufficient amount of time, they will eventually fly away.

'Rounder 2
'Rounder 2 is a pair of larger versions of the 'Rounder. They're the boss for the first Mr. X's stages, at the top of what seems to be the outer wall. They run back and forth on a track while dropping bombs and trying to hit Mega Man. They're vulnerable to the Flame Blast and a charged attack from the Power Adapter, which is able to change their direction.