Warmworms are aggressive, but immobile creatures living in the Stalactite layer and also in the Lava layer underground, spawning on Hardened Lava, Igneous Rocks, Tourmaline, Sulfur, Diamond Nodes and other blocks. They can spit lava-fountains and inflict fire damage. Warmworms will only spawn in darkness, but they can withstand sunlight. If you tame them to become your Pets, they cannot follow you through normal means, because they are rooted in the ground.