Galmus has a red, lumpy body with it’s mechanical interior shown on the side of it’s abdomen. It has an upside-down face with yellow eyes and has spikes on it’s limbs with sharp metal claws. It also has yellow spikes on it’s spine and two on it’s waist. It’s most noticeable appearence are it’s two back shells with spikes all over which it can use to form into a ball.

A group of aliens called, Campbellians, have started their attack on Earth after being reawakened in the early 21st Century. Oreana, the leader of the group, tells her General, Garuda, to send out a Slave Monster. Garuda gets Narua to summon a Slave Monster, so Narua summons a Slave Monster hibernating in solid ice. He then shoots laser around the block of ice, causing it to melt and awaken the Slave Monster within the block ice, Galmus. The Slave Monster appears in the human world out of a mountain where is causes a landslide. Galmus then closes it’s two back shells around it, forming into a ball so it can destroy a nearby town. After destroying the town, Galmus burrows into the ground while still in ball form.