Locked Chests

Locked Chests
The Locked Chests are a special type of chest found scattered throughout the Hellish Dungeon. They must be opened with a Soul Key, and cannot be opened any other way. Upon being opened with a Soul Key, the chest will become a mimic, and a fight will ensue. Once the mimic is defeated, it will drop a powerful item.

Types
There are 9 different Locked Chests in the Hellish Dungeon, each one corresponding to a particular biome in the game, thus is why they are often referred to as the later hardmode version of the Biome Chests in the hardmode Dungeon. The 9 types are: Jungle, Desert, Corruption/Crimson (based upon which is generated into the world), Tundra, Hallow, Mushroom, Ocean, Forest, Underworld. Each type has its own unique mimic fight and different drops.