Underground Crimson

The Underground Crimson is a Hardmode Biome, being one of the biomes that spawns when the Wall of Flesh is defeated. It is the underground version of the surface-level Crimson, and appears at and below the cavern layer. It operates similarly to surface Hardmode Crimson, being comprised of Crimstone and Crimsand, though it spawns different enemies. Underground Crimson spreads just like surface Crimson, and similarly can not spread to The Hallow (nor to Underground Hallow).

Underground Crimson does not suppress the spawn of other underground and cavern enemies.

''Note: Most characteristics of surface Crimson apply to the Underground Crimson, with the exception of the enemies that spawn. See Crimson for more extensive information.''