Mimics

A Mimic is an uncommon Hardmode enemy disguised as a Chest, appearing as the appropriate Chest type for the environment.

Mimics can be spawned by the player using the Chest Statue, even prior to Hardmode (Mimics spawned this way do not drop any coins or items besides the Mimic Banner).

Rare Hallowed, Corrupt, and Crimson Mimics can also be spawned manually by players via a Key of Light or Key of Night (see Special variants below).

Mimics are immune to the Poisoned, On Fire!, Cursed Inferno, Venom, and Shadowflame debuffs.

Battle potions can also help increase its spawn rate due to how rare it is.

Common variants
Ordinary Mimics look exactly like Chests until approached or attacked, at which point they come to life and chase the player. Before revealing themselves, they take on the appearance of chests normally found in the biome they are found in: regular Chests above the Underground layer, Gold Chests Underground, and locked Shadow Chests in The Underworld.

Mimics that spawn in a Snow Biome take on the appearance of Ice Chests, and also have their own unique set of ice-themed drops.

The Present Mimic is a Frost Moon variant that behaves similarly, but drops several hearts instead.

Special variants
These Mimics are more rare, have much higher health, more advanced attacks, and separate sets of unique drops. They are biome-specific, and only spawn in the vicinity of the underground version of their corresponding biome. Like ordinary Mimics, they only spawn in Hardmode worlds. The Jungle variant is currently unimplemented, and never spawns during normal gameplay.

Similar to ordinary Mimics, these disguise themselves as Chests until approached or attacked, except that they do not resemble any ordinary Chest type currently in the game. They are larger than actual Chests, and larger than the ordinary Mimics listed above.

The Hallowed, Corrupt and Crimson Mimics can also be summoned manually by the player, in Hardmode worlds only. This is done by placing a Key of Light or a Key of Night inside an otherwise empty Chest, which will then become a Mimic when closed. The type of world a player is in determines whether a Corrupt or a Crimson Mimic is summoned with this method.

Each of the four have the same attack methods:
 * The Mimic jumps towards the player, and can jump very high.
 * It periodically shuts itself and remains stationary, during which it becomes invincible to attacks. In Expert mode, it will reflect players' projectiles that can damage players.
 * It performs a "pound" attack, whereby it leaps into the air above the player and swiftly drops down, like a Giant Tortoise. However, Mimics can travel through blocks during this attack unlike Giant Tortoises.
 * If the player attempts to escape, the Mimic dashes after the player at high speed (slightly over 51 mph). This attack can also travel through blocks.

Identification
While disguised, Mimics will not show a usual enemy tooltip when hovering the mouse cursor over them, except in the mobile version. Below are some tips to help differentiate real chests from Mimics.
 * Hitting a disguised Mimic with any weapon, including ranged weapons, homing weapons, or a Minion, will make it activate.
 * Real Chests will show up on the minimap, but Mimics will not.
 * Spelunker Potion will not cause a Mimic to glow, but the Hunter Potion will. The Spelunker buff causes only normal Chests to shine, while the Hunter buff colors all enemies red.
 * Mimics disguised as Gold Chests or Shadow Chests will not produce their usual animated sparkle effect, as opposed to real Chests.
 * The Lifeform Analyzer will detect nearby Mimics. The Metal Detector can also give them away, as there will be no "Chest detected nearby!" message. (Provided there actually are no chests nearby)
 * Mimics may not line up properly with blocks, as normal Chests would. They can also spawn halfway inside blocks, partially hanging off a block over empty space, or in front of background objects and other enemies, where real Chests can't be placed.
 * Mimics cannot disguise themselves as unlocked Shadow Chests. Unlocked Shadow Chests are always real Chests. Similarly, they cannot disguise themselves as locked Gold Chests, which appear in the Dungeon.
 * If a Mimic spawns in Lava, it will take ticks of damage, even while it is not yet attacking the player.
 * Any Gold Chest found outside of Underground Cabins in maps made in version 1.3 and above is a Mimic. Gold Chests are not naturally spawned outside of Underground Cabins anymore. However, on rare occasions, a Gold Chest may spawn below or beside a Cabin due to structural generation errors.
 * As of version 1.3.4, you can right-click on a Chest with any minion summon weapon. If it's a Mimic, a purple indicator will show up, but your minions will not attack it.
 * In the and, mimics can be identified by their lack of yellow border (normally around chests) upon getting near them.

Tips

 * Be careful when mining near the Underground Crimson/Corruption and Hallow Biomes very early in Hardmode, lest a Biome Mimic spawns and catches the player unaware. Carrying a Lifeform Analyzer, R.E.K. 3000, PDA, or Cell Phone in the inventory can help  warn the player.
 * Targeting Mimics can help players making their way through early Hardmode, as they drop high-damage weapons and good defensive accessories, as well as around (even up to  in expert mode), which can help with Hardmode's higher prices.
 * An easy way to kill Mimics early in Hardmode is to grapple a high place and attack with a ranged weapon. This does not work on special variants, due to their enhanced jumps.
 * Any special variants of mimics can easily be defeated in early hardmode on flat ground and while riding a Basilisk pet, helping you gain extra speed to dodge attacks and having slanted horizontal blocks to the left or right going upwards. This gives you some time to go to the other side and restore Health or Mana and it also helps while going back and forth to dodge the Mimics Jumps, Invincible state and pouncing.
 * Key of Light/Night spawned Hallowed and Corrupt/Crimson Mimics can be easily defeated by using a platform very high in the air, such that the Mimics can barely reach you. They will jump up constantly from the surface below (which will be a little off-screen), in such a way that they are very easy to dodge with minimal movement. Note that they will be able to do a pounce and potentially can jump on the platform.
 * With 3 or more players, Mimics will never stay in their disguised state.
 * Biome Mimics will travel through blocks in the duration of some of their attacks so simply grappling to a high spot will not work on them like it would on their less powerful relatives.
 * In Expert mode, firing at a Biome Mimic with a high damage, single hit weapon such as the Sniper Rifle should be avoided. The reflected projectile from the said weapon can easily kill the player, especially when unprepared.

Trivia

 * Mimics first appeared in the   in 1977, and have appeared in countless publications since.
 * When Mimics were first introduced, it was possible for them to appear as a Skeleton instead.This was later fixed after an unknown update.
 * Lost Girls act like the Mimic; they disguise and then reveal themselves to be Nymphs and try to kill the player.
 * Biome Mimics are the only non-boss enemies which are manually spawnable.
 * Despite their name, biome mimics do not actually resemble Biome Chests such as a Crimson Chest found in the Dungeon.

History
宝箱怪 Mimic