Stalactites. They can be made out of several various materials (ie. Magmarock, Cobblestone, Unrefined Wood...) and can be harvested for supplies and to prevent damage from them.
- When touched the Thorn Structures will damage the player.
- They spawn on the top surface of 2 adjacent blocks deep underground.
- Thorn structures regularly give off dark reddish particle effects that look like a skull and cross-bones as a warning.