Worm

The  is a mob that has a chance to spawn when mining inside the crystal hollow. Breaking Hard Stone, all ore type and mithril can trigger the worm spawn equally. It is unknown if breaking gems can spawn worm.

Spawning
In order for the worm to spawn it checks the block a player is standing and its surrounding block then checking for the 1 wide 2 high tunnel in the x and z directions. If the tunnel is long enough (around 5 block long or more) the worm will have a chance to spawn upon breaking the next block. There are still a lot of unknown variable that the game checks for spawning worm. For example, after digging out a 1 wide 2 high tunnel, you can run back and break all the block at player's eye level on the side and that would still trigger the spawn condition as disscussed above. However, it only works on the first and second (possibly third) layer that the player ran back and forth to get. Becarefull to keep the rail (the bottom blocks right below the players eye level blocks) intact for the spawn condition to be met.

Tunnels dug by Armadillo Pet that create a 3 block high tunnel will not spawn worm. However, it occationally ran into ores or mithril on the top 3rd block, that the Armadillo can not mine, for long ehough which will still trigger the worm spawn. Another exception to this is using the armadillo pet near the top bedrock layer. This makes the top/ 3rd block bedrock which means the armadillo can only make a 2 high tunnel which will spawn worm. While spawning, they make a unique squelching sound 3 times, alerting players of their presence.

Usage
They have the appearance of the Scatha Pet. They appear as a chain of heads with the same texture of the Scatha Pet. Every hit will remove 1 from their health, similarly to Spooky Festival mobs. They start off with a chain of 5 segments, and decrease by one each hit until killed.

Upon spawning, they will slither away from the player.

Trivia

 * When using the Mole perk, the player will not be able to spawn Worms because the tunnel dug will not be 1x2. However, if the player mines in the west direction, they will be able to spawn Worms.