The Hallow

The Hallow spreads similarly to evil biomes, converting nearby susceptible tiles, and defeating Plantera reduces its spread speed by 50%.^[1][2] The Hallow cannot spread through mud areas such as those in Jungles or Glowing Mushroom biomes.^[1] A Hardmode surface biome, the Hallow features cyan grass, multicolored trees, a large rainbow in the background, and pastel-colored fairytale graphics.^[1] Directly under a naturally generated Hallow biome sits the Underground Hallow.^[1]

Except for certain special or secret world seeds, the Hallow is absent from newly generated worlds.^[1] Defeating the Wall of Flesh for the first time creates a diagonal stripe of Hallow from the surface to the world's bottom, converting applicable tiles to Hallowed variants.^[1]