You had better pace yourself: Just work on defeating all 100 each day, and keep coming back for three days to do it again. If we luck out, after three days that should drive them away for awhile.
We've counted 100 of these enraged Mimics in the Factory, and as soon as you wipe them out, a new pack of the creatures arrives in their place. You'll need to kill all 100 of them each day for three days.
Slugrats have taken over the Gearlock Factory! These Mimics are enraged, and they're much stronger and sturdier than common Slugrats. They scurry across walls and ceilings so they can be tough to find, but thankfully they've confined themselves to only the Gearlock Factory.