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. It has four hatches, each with the same amount of health. 

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.

Strategy
GearBank is a simple sub boss, but the amount of health it has can drag out the fight. With proper timing and accuracy, one can hit all the hatches simultaneously with a charged Z-Saber, inflicting massive damage to it. The EX Skills Burning Shot and Time Stopper are also good choices too multi hit. The SerpentGears are easy to defeat, but become faster one the hatches lose more health, making them a nuisance. All the saber skills can wipe them out quickly, so this is recommended to focus on GearBank itself.