The subterranean sections of the Hallow are populated by creatures who drop Souls of Light, a valuable crafting material for Hardmode Items. Swarming is a major concern in the underground Hallow.

Terraria's Hardmode is the most difficult version of the game, ... Corruption and Crimson, as well as the Hallow, ... Make sure to stay in the Underground Jungle for the duration of the fight.

Terraria has many achievements to unlock. ... Craft a Drax or Pickaxe Axe using Hallowed Bars and Souls. Photosynthesis: ... the rare zombie that appears in the Jungle and Underground Jungle at night.

To find a Gelatin Crystal, head to the Underground Hallow. They are bright pink and there's a good chance one will spawn near the Crystal Shards , so once you've found one, go ahead and mine it.