Mimic

Location Dungeon Levels 5–6
Damage 126–127
Notes Appears to be a chest
Mimics appear as chests, and the game even labels them as chests until you attack them. Be wary of any chests you see on Dungeon Levels 5–6, especially if they start moving. It's not a bad idea to Attack chests on sight, just in case.
Compare Mimic to other Creatures
Ettin Lizard man

Related

Mimic

Location Dungeon Levels 5–6
Notes Appears to be a chest
Mimics appear as chests, and the game even labels them as chests until you attack them. Be wary of any chests you see on Dungeon Levels 5–6, especially if they start moving. It's not a bad idea to Attack chests on sight, just in case.

Chest

Experience 4
Chests will only attack you in one place, Castle Fire. You won't need treasure at this point, and they're behind locked doors, so really these fights are just punishments for greed. Chests aren't very tough, just unexpected.