These millipedes mutated to an enormous size. They retained the ability to burrow underground, and preferred a subterranean environment, though would surface if hunger overwhelmed their natural instincts. The size they could reach was so vast, that it could destroy roads above in a manner comparable to an earthquake, as their burrowing left huge, vast, and unsupported tunnels underneath. The Grave Digger lays eggs in the ground and sewers typically in clutches of a hundred. When they hatched, the larvae; known as "Sliding Worms", would transform into new Grave Diggers themselves after a week.