Hallowed Mimic

Hallowed Mimic is a Mimic monster that spawns in the Underground Hallow or when you put a Key of Light into an empty chest in a Hardmode world (with autopause disabled). It is a stronger version of the normal Mimic with several new moves that drops unique weapons themed after the Hallow. Like all other mimics, it will disguise itself as a chest until attacked or if a player comes close to it, though the biome-exclusive mimics do not resemble any chest currently in the game.

Hallowed Mimics attack by jumping towards the player, like other mimics; however, they also have the ability to shut themselves, during which time projectiles will be reflected back towards the shooter. They can also perform a pound-like attack in which the Mimic leaps over the player's head and swiftly drops down. Be warned that the Mimic can chase you at high speed if you run far enough. It can dash at high speeds, and can sometimes dash through walls.

Due to their high health, defense and damage, as well as their powerful drops and their ability to move through walls, they and the three other biome-specific mimics (Corrupt, Crimson and Jungle) can be considered something of a miniboss