Glumbums are sinister spirits created from Peklo's melancholy when Nightmare was slain by the Successor. They appear as long sheets of sleek jet hair. Under these heavy curtains of hair are snow-pale humanoids with the physique of an Immortal band member. Although evidence for their body has been documented with photographs, these photographs were usually recovered from the charred remains of the photographers. The only known ability of a glumbum is its ability to breathe fire. Self-made recordings exist of glumbums running around, especially in frostbitten forests. Glumbums tend to reside in fresh interments, so that when humans exhume the recently deceased for signs of vampirism, they can strike. For this reason, the ritual now employs mercenaries and wandering vagabonds to protect the undertaker. The presence of a glumbum is often indicated by a soundscape of heavy metal shredding and monstrous growls surrounding a community.

Villages that stopped exhuming corpses were quickly overwhelmed by hordes of glumbums and vampires. These villages were later fashioned into makeshift caravansaries by the creatures for traveling demons. These caravansaries offer a variety of burgers and spirits so delectable that some food critics have gone undercover to taste the legendary demonic cuisine.