Key of Light

This turns a chest into a Hallowed Mimic wherever you are standing. You do not need to be in the Hallow and you do not need to go hunting, which is the whole point: the natural version spawns on its own schedule and this one appears when you decide it should.

Be ready before you trigger it. The mimic materializes right where the chest was, so set up your arena, buffs and escape route first rather than opening a chest in a corridor and finding out how fast it moves.

The spawn is fussier than it looks, and most failed attempts come down to one of these.

• The chest has to hold the key and nothing else. One stray torch and nothing happens.
• It has to be an actual chest. Barrels and other storage containers will not do it.
• Closing the chest is what fires the spawn, so opening a different inventory screen straight afterward skips it.
• Pulling the key in with wiring does not count. It has to go in by hand.
• Autopause holds everything until you unfreeze the game, and on console it blocks the spawn outright.

The chest is consumed along with the key, so use the cheapest wooden one you have rather than an ornate build piece. The Key of Night works the same way for the Corruption and Crimson version.