Auto Counter

Auto Counter is the name for two varieties of the same enemy from Mega Man ZX. They both appear as a cannon that is constantly expanding and contracting to blow out air from a series of small vents on its sides. It does not fire until it is hit with a Buster shot or slashed with the Z-Saber, after which it will fire either a series of shots from its top in arcs that fall back on top of the player.

Auto Counter
This variety is colored turquoise and purple with round red gems on each side. It fires what seems to be popcorn upon being attacked, which makes sense because it only appears in the amusement park, Area H. 

Auto Counter Flame
This slightly larger variety is colored different shades of red and orange with hexagonal red gems on each side. It launches fireballs upon being attacked that will arc back down to the ground and explode like bombs. It appears in Area G Fire Site and Area K Lava Field.