Biome Key Molds

Biome Key Molds are extremely rare Hardmode crafting materials used to craft Biome Keys, which open Biome Chests. After the Wall of Flesh is defeated, every enemy has a 0.04% (1 in 2500) chance of dropping a Biome Key Mold. The type of Biome Key Mold that is dropped depends on the biome you are currently in (Jungle, Corruption, Crimson, Hallow or Snow).