Potton[1] is an enemy first appearing in Mega Man 3. It is a red and grey robot head stuck inside a domed glass jar, which uses a propeller to fly around and can drop its contents to attack.
In Mega Man 3, Pottons are only found in Snake Man Stage among the initial Robot Master stages, but later reappear in the Doc Robot version of Gemini Man Stage. They fly left and right, usually high above Mega Man, and turn around only when they touch a wall. When Mega Man is directly under them, the glass jar opens at the bottom, dropping the robot head inside, which disappears when it hits the ground or can be destroyed through damage.
After dropping its contents, the jar stays intact and continues to fly back and forth, though it remains empty and unable to attack (except through contact damage) unless the Potton is respawned entirely by scrolling the screen.
Mega Man III
Sprite from Mega Man III.
Pottons reappear in Mega Man III on the Game Boy, acting identically, though with a higher tendency for the jars to get in Mega Man's way due to their lower placement. They appear only in Snake Man Stage.