Cavern Lurker Dragons are nocturnal ambush predators. Although small, they are very aggressive and will attack anything weak enough to be overpowered. Their preferred method of hunting is to lie in wait in a cave, burrow, or other small, enclosed space; when any potential prey passes they will lunge out to grab hold of the unsuspecting victim and drag it back into the lair. Cavern Lurkers have an odd aversion to sunlight and almost never venture out during the day. More commonly sighted are the odd piles of bones they stack near the entrance to their dens. Their mating call is a low-pitched bumping noise.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Tomb Crawler lives in an old tomb, once planned to be a human ruling family's burial ground, but they were deposed and the building project abandoned. Over about nine years, he dug deeper through the floor of the tomb and appropriated some of the cavern spaces around it. His home below the tomb is made of yellow and reddish rock, with the occasional wall of hardened sand. He shares it with snakes, ghouls, large insects, sturdy lizards, and half a dozen other dragons who've managed to get used to living in the area. Few outsiders visit Tomb Crawler's tomb, and even fewer venture farther downward to see him and the neighbors. In the darkness, one can determine when Tomb Crawler is nearby from the distinct shuffling he makes as he runs along the walls.