Massive midnight blue creatures residing under Mythic, TX, the wurms exude a strange acrid bluish fluid. They appear to be responsible for attacks on livestock at the Standish Ranch and for the abduction of Janie Horowitz. How they got into Mythic to do all these things, no-one knows.
It would appear that the wurms reproduce by implanting larvae in living hosts, which then anchor themselves to the hosts muscle and bone tissue. The larvae are in all respects miniature versions of the parent. Samples of the larvae extracted from Janie have been sent to the FBI for further study.
There is a possibility their skin might have beneficial effects, if prepared properly. Or failing that, in a motel kitchen.
Either way, they've proved tough opponents, nearly killing Theodore who was only saved by the timely intervention of Lacey Leveaux.