(evil, extraplanar, lawful)
Source: The Infernal Syndrome, pg(s). 84
Cerberi serve as the watchdogs of Hell itself, though they are far more intelligent than their bestial form would imply.
The cerberi most closely resemble some sort of terrible, fiendish hound. Their body has a similar structure to that of an enormous canine, four foot tall at the shoulder and weighing more than 200 pounds, except that all its muscles are exposed as if it had all its skin torurously peeled off. Almost as disturbing is the cerberi's three fearsome heads. These heads each resemble a wolf skull that is mostly covered in exposed muscle. The eyes are the clearest indication of the cerberis' fiendish heritage as the instead of eyeballs their eye sockets are filled with ever burning hell fire.
Habitat & Ecology
Cereberi thrive in the burning depths of Hell. Renowned as savage, violent guardians cerberi are most common on the first three layers of Hell serving as bestial trackers for the devilish armies of Avernus, intelligent guard dogs for the decadent estates of the city of Dis and silent guardians of the benighted vaults of Erebus. When not serving fiendish master cerberi can be found in large packs that roam the wildernesses of Hell (and occasionally elsewhere) tormenting and destroying damned souls. Cereberi can often be found beyond Hell as they are valued for their abilities as trackers and jailers, they are sold in the flesh markets of Dis to evil creature from across the planes. Their favored buyers are normally night hags and daemons.
Cerberi are supposedly descended from one ancient, mythical sire, an infernal beast that still guards some forgotten corner of Hell. They are distant cousins of the more common Hell hound but they loathe their lesser kin, tearing them to pieces if given the chance. Cerberi embody the covetous, greedy nature of Hell, which gives rise to their unique ability, any creature they bite is trapped, unable to leave the plane they are on. Most often their bite serves to keep a soul trapped in the depths of Hell. While the cerberi may superficially resemble twisted canines their ecology has far more in common with the fiends than it does with beasts. They do not need to eat though they greatly enjoy the sensation of biting then tearing creatures to pieces. The most surprising part of the cerberi's ecology is their intelligence, they are far smarter than the beasts they resemble. While not as smart as humans the cerberi's intelligence is entirely focused on causing pain and suffering. Because of their bestial form many underestimate the cerberi, it is usually the last mistake they ever make, many a villain who thought of his cerberi as a guard dog has found himself torn to ribbons by his all too intelligent underling.
The Malbolgian cerberi are a distinct sub-breed of the cerberi. They are larger, fiercer and far more dangerous. The Malbogian Cerberi get their name from the layer they are breed on Malebolge, a layer devoted to the training of fiendish armies for use in Hells' on going wars. Here in nightmarish breeding pens cerberi are forced to breed with the hated hell hounds known as Nessian Warhounds, the offspring of these unholy unions have the appearance of the cerberi but gain the huge size of their Nessian parent, they also gain some of the hell hounds fiery breath, their bite burning with infernal flame. Malbogian cerberi stand over six feet high at the shoulder and weigh over 400 pounds.