Mimic

s are a type of enemy that look like wooden, frozen, golden or locked shadow chests. They will stay still initially, but will reveal themselves by jumping and biting the player if he/she moves within their attack range. Another way to reveal a Mimic is to shoot it from a distance. If the chest is a Mimic, it will take damage and move to attack the player, revealing itself in doing so.

Unlike regular chests, Mimics will not glow while under the effects of a Spelunker Potion, making it easy to differentiate between a Mimic and a standard chest. They do, however, glow under the effects of the Hunter Potion. Similar to their passive counterparts, Mimics are usually found underground, but can rarely appear on the Surface in front of natural background walls. Mimics will also appear on maps for the console version of the game.

The Mimic is a Hard Mode monster, so it cannot be encountered naturally before the Wall of Flesh is defeated. Mimics can be spawned by powering the Chest Statue, but they will only drop the Mimic Banner when spawned this way.

Trivia

 * Monsters that trick the players by disguising themselves as treasure chests are common place in many RPGs, mainly dungeon crawlers where treasure chests are common enough to make the player unsuspecting. The vast majority of them are also called Mimics.