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. Autopause must be disabled for this to work, and the world must be in Hardmode. The key must be the only item inside the chest.

History
Clé de la Nuit