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 and drops unique weapons. It drops powerful items, like all mimics. 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. See the Mimic page for more info.

The hallowed mimic jumps after you like a regular mimic but will also use three different leap attacks and sometimes close itself. When it closes ranged attacks will bounce back towards you. The leap attacks consist of either 3 short but fast leaps towards you, one long fast leap which ends when the hallowed mimic is close to you, or a kirby-like attack where the hallowed mimic leaps above you and then down onto you.

Suggested farming method: Create Key of Lights and put them in empty chests outside your base. Prepare a short and wide flat area. Use ranged weapons and keep your distance. When the hallowed mimic leaps for you simply jump over it.