Key of Night

The Key of Night is a craftable item that spawns a Corrupt Mimic or a Crimson Mimic when placed inside of an empty chest, depending on whether the world generated with The Corruption or The Crimson, respectively. The world must be in Hardmode and the only item inside the chest must be a single Key of Night.

Spawning the Corrupt/Crimson Mimic consumes both the Key of Night and the chest.

History
Schlüssel der Nacht Clé de nuit 밤의 열쇠 Ключ ночи