Rotfiend

Course it reeks. Think they're called rotfiends because they smell like roses? — Vesemir, witcher of the Wolf School

Skinless Rotter. What rotfiends are, everyone can see. Even seeing them is not necessary, as hearing their name should be enough to tell anyone what creatures might bear this unpleasant title. Rotfiends resemble decomposing human bodies that have been mostly stripped of their skin. Their presence is given away by the overwhelming stench of rot which gives them their name.

Pack Scavenger. Similar to ghouls, rotfiends roam in packs. Rotfiends are undead, so usual tactics against this kind of creature might apply. Common poisons, on the other hand, are useless - the beasts have gained immunity to these by devouring carcasses. Killing a rotfiend is not difficult, yet one must remember to survive the moment of the beast's death, for the monster's corpse releases explosive fumes a mere spark could ignite. The resulting explosion can easily kill an adventurer, but it might also kill nearby rotfiends, creating something of a chain reaction. Thus, a dying monster should be drawn away from its kin.

Hysterical Strength. Backed against a wall, a rotfiend flies into a fury, attacking madly. This attack should be evaded, for the beast's chaotic blows carry a strength that can only be called hysterical. Running is never a good idea when fighting rotfiends, as the creatures will pursue its foe, jump on its back, knock it down and overwhelm it. Stopping rotfiends from escaping can be difficult as they try to burrow into the ground.

Unwelcomed Resurgence. Rotfiends and devourers were once rarities, but in age of constant warfare and violence they can become a veritable plague, as they feed on carrion and human corpses, particularly around battlefields, near cities afflicted by plague, or around villages touched by famine. They appear of a sudden, and disappear even more quickly if threatened, so exterminating them is difficult. They are best dealt with by cutting off their food supply, which is, burning all corpses in the area. Corpses must be incinerated rather than buried, for rotfiends are avid and skillful diggers. Without sustenance, the beasts will leave in search of new feeding ground. See a rotfiend and you can be sure there are many more in the area. They usually feed in large groups and thus present a danger to lone travelers – especially considering their speed, which can be more than a match for a horse at full gallop. Rotfiends and devourers feed in the twilight hours and at night, when they become much more dangerous than during the day.

Undead Nature A rotfiend doesn't require air, drink or sleep

Flesh Rot (see contagion spell)

Many academies throughout the world have studied the remains of rotfiends, hoping to explain their sudden and recurrent return. They have yet to find the answer to their question but one troubling fact might lead them on the right path: the corrupted tissues of the undead always reveal the presence of the flesh rot disease. Most concluded that the two phenomena are inherently connected: a flesh rot outburst is followed by a resurgence of rotfiends and rotfiend infestations are always followed by numerous cases of the disease.

• Alternatively, a creature that takes damage from a rotfiend must make a DC 13 Constitution saving throw, contracting the flesh rot disease on failure, as per the contagion spell.

Scurver

Old Corpse Eater. Scurvers are rotfiends' larger cousins. The bodies of these hideous, vaguely humanoid creatures are covered in rotten scraps of flesh, under which lurk even more rotten muscles stretched around a strong, flexible skeleton. Scurvers, which feed on old, rotting corpses, prefer to make their hunting grounds in abandoned torture sites, forgotten graveyards, and old battlefields. They are very aggressive and, though they feed on corpses, if they come across a living person they are likely to attack.

Razor Spines. Scurvers usually feed underground, but sometimes, when they catch the scent of a human, they crawl to the surface in a matter of seconds and attack their potential prey. While fighting them one cannot afford to forget about their special boney spines, razor sharp protuberances sticking out from their skeletons. When a scurver is near death, the gasses and enzymes gathered within its body cause it to explode, flinging these spines out at great speed, turning them into one last deadly weapon in their arsenal.