Cyst is portrayed as wielding a shotgun. Cyst seems to suffer from neurofibromatosis, which explains the reddish lesions covering his body. He also walks with a limp and has a large neck brace grafted to his body. Cyst is first seen by Doug Bukowski dragging a female corpse through the nuclear test village. As Doug hides behind an old generator, his dog Beast draws Cyst's attention when he lets out a whimper. Dropping the rope he was using to drag the female body, Cyst inspects the area Doug and Beast are in, but soon stops his searching after finding nothing (Doug and Beast had hid in a nearby wrecked car) and starts to drag the body he had earlier away again.
Cyst is encountered again by Doug as he leaves Big Brain's house; hiding, Doug waits as Cyst stops patrolling to cock his shotgun before he attacks him, hitting Cyst in the knee with an axe and knocking him to the ground. With Cyst helpless, Doug proceeds to axe him in the back before killing him using the pick end of the axe, impaling Cyst through the eye with it. With Cyst dead, Doug steals his shotgun and leaves his axe behind.
The shotgun cyst had belonged to the old gas station man.