So how do mimics create more mimics. Like are they born through eggs or fully formed creatures albeit small, and they grow tough shells and shed them as they get bigger (kind of like lobsters, spiders, crabs). And those discarded shells are used as the normal chests.

All shall be answered within this series.... maybe.

Base +10

Or maybe mimics are magical creatures, created by spell-casters like golems, and don't reproduce naturally at all?

Base +4