Worm

The  is a mob that has a chance to spawn when mining Hard Stone in the Crystal Hollows, and has the appearance of the Scatha Pet. They appear as a chain of heads with the same texture of the Scatha Pet. Every hit you deal will remove 1 from their health, similarly to Spooky Festival mobs. They start off with a chain of 10 segments, and decrease by one each hit until killed.

Spawning
They appear to spawn in small tunnels (1 block wide, 2 blocks high) and will spawn within around 3 seconds after an area has been dug out. While spawning, they make a unique sound, alerting players of their presence.

If using the Mole perk at HOTM 6, you will not be able to spawn worms.