Mimics

Mimics are uncommon Hardmode enemies disguised as chests, appearing as the appropriate chest type for the environment.

Mimics can be spawned by the player using the Chest Statue, even prior to Hardmode. However, 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 the Biome Mimic section below).

Common variants
Ordinary Mimics look exactly like chests until approached or attacked, at which point they come to life and chase the player by hopping towards them. Before revealing themselves, they take on the appearance of chests normally found in the biome they are encountered 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 is a Frost Moon variant that behaves similarly, but drops several Hearts instead.

Special variants
Biome Mimics are rarer, and much more powerful in every way, than the normal Mimics -- indeed, they are more dangerous than any pre-Hardmode boss, except perhaps the Wall of Flesh. However, each type has their own set of unique drops, including weapons and tools that have few equals short of the Lunar Events, 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, the special variants disguise themselves as chests until approached or attacked, except that they do not resemble any 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 natural evil biome of the world a player is in determines whether a Corrupt or a Crimson Mimic is summoned with this method.

Each of the four has the same attack methods:
 * The Mimic hops toward the player, much like a normal Mimic would.
 * It performs three rapid dashes, during which it can also jump extremely high.
 * It periodically shuts itself and remains stationary, during which it becomes invincible to attacks. In Expert mode, it will reflect players' projectiles which can damage them.
 * 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). It can also travel through blocks when using this attack.

Identification
While disguised, Mimics will not show a usual enemy tooltip when hovering the mouse cursor over them. 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.
 * On the, Mimics can be identified by their lack of yellow border (normally around chests) upon getting near them. A Mimic will also appear as a red dot on the map, as all enemies do.
 * 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, Ice Chests, or Shadow Chests will not produce their usual animated sparkle effect, as opposed to real chests. This does not work for Wooden Chests/Mimics.
 * This is especially apparent when there seem to be two chests nearby each other, which may rarely happen. If one of them is shining and the other one is not, the one that is not shining is a Mimic.
 * 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 real 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 cannot 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 generated in version 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, beside, or above a Cabin due to structural generation errors.
 * As of version, minions can be directed to target an enemy by pressing with a minion summoning item on an enemy. If it is a Mimic, a purple indicator will show up.

Tips

 * The only two damage-inflicting debuffs Mimics are not immune to are Frostburn and Suffocation.
 * Battle Potions and Water Candles can be used to increase the chances of spawning, as with any rare enemy.
 * If a bridge was built in the Underworld to defeat the Wall of Flesh, Mimics can be found easily by walking back and forth and watching the.
 * Due to their low jumps, they can be pretty easily dealt with by using a ranged weapon while standing out of their reach on a Rope.
 * During February, all enemies have hearts floating on them. This makes the difference between mimics and chests blatantly obvious.
 * With 3 or more players, Mimics will never stay in their disguised state.

Biome Mimics

 * Biome Mimics, despite being significantly tougher, drop less money than the normal variants. However, their item drops tend to be far more useful and valuable. Besides advanced weapons and tools, they drop Greater Healing and Greater Mana Potions, which are handy in early Hardmode, before the player can craft their own.
 * Players should 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 or one of its upgrades 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, which can help with Hardmode's higher prices.
 * Biome Mimics can easily be defeated in early Hardmode on flat ground and while riding a, helping the player gain extra speed to dodge attacks and having slanted horizontal blocks to the left or right going upwards. This gives the player 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 Mimic's jumps, invincible/deflecting state and pouncing.
 * Biome Mimics that are manually summoned can be easily defeated by using a platform very high in the air, such that the Mimics can barely reach the player. They will jump up constantly from the surface below (which will usually be slightly 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 can potentially reach the platform.
 * 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 said weapon can easily kill the player if the Mimic is closed, especially when unprepared.
 * If auto pause is turned on when placing a key into a chest to manually summon a biome mimic it will not summon one. In order to fix this, turn auto pause off in the settings and place the key inside the chest once you have done so. A mimic should spawn now
 * A decent way to kill them, if you have a Hellevator, is to spawn them in The Underworld, and use rope to climb up the hellevator, shooting them with a weapon such as the Shadowflame Knife. Assuming you're on a medium world, and using said weapon, the biome mimic should be almost, if not dead by the time you reach the top.
 * It is believed that the reason why the Jungle Mimic is unspawnable is because while the Jungle itself is big, the tunnels and caves of the Underground Jungle are mostly small, so players would get killed almost instantly by the Jungle Mimic. It can still be spawned through third-party software and hacks.

Trivia

 * Mimics first appeared in the  , the primary bestiary sourcebook for monsters in the fantasy tabletop role-playing game , 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 similar to Mimics; they disguise and then reveal themselves to be Nymphs and try to kill the player.
 * Biome Mimics are the one of the two non-boss enemies which are manually spawnable (excluding enemies spawnable with using statues). The others are wraiths, which can be manually summoned by breaking an altar.
 * Despite their name, Biome Mimics do not actually resemble the Biome Chests found in the Dungeon. In fact, they do not completely resemble any actual chest in the entire game making them easy to identify.
 * Putting a Key of Light or Key of Night in a chest, and then selecting another chest will not summon the corresponding mimic, while keeping the key in the chest.
 * Despite not spawning through regular gameplay, Jungle Mimics are still detected by the Lifeform Analyser.

History
Imitation 宝箱怪