GearBank

GearBank (ギアバンク) is an enemy from Mega Man Zero 4. It appears as the sub-boss of Hibernation Chamber, Fenri Lunaedge's stage. He has four hatches. Each hatch spits out a stream of Serpent Gears that follow Zero, hence the name GearBank. The more Zero damage it, the faster the gears run at him. The player has to destroy all 4 hatches to defeat it.

Serpent Gear
Serpent Gear (サーペント・ギア) is the Mechaniloid spat out by GearBank in an attempt to run over Zero. They drop parts when defeated.