Fiendish dragons are a category of planar dragons from the Dungeons & Dragons fantasy role-playing game, who are found on the lower planes and who tend to be evil.
The planar dragons, including the howling dragon, the pyroclastic dragon, the rust dragon, the Styx dragon, and the Tarterian dragon first appeared in Dragon #300 (October 2002). They appeared again in the Draconomicon (2003).
Howling Dragon: This dragon is found on the Windswept Depths of Pandemonium. They are very gaunt, small dragons who are covered in purple scales and have very thin, but powerful, wings. Their head is covered in a mane of bristly, violet, spines and their eyes, bright red or yellow in color, are large and demented. When another creature stares into their eyes, they can feel this dragon’s insanity.
Pyroclastic Dragon: Found in the Bleak Eternity of Gehenna, this diabolical dragon looks as if it were entirely made from brimstone. It is a heavy-bodied species with ashen colored scales. Its skin bares cracks that are red, orange, or yellow in color. Though its wings appear flimsy, they are strong enough to support the creature. Pyroclastic dragons are best described as unpredictable and destructive, much like the volcanic terrain they inhabit.
Rust Dragon: This dragon lives in the Infernal Battlefield of Acheron. It is a strange type of dragon, and usually the least evil of its kind. It somewhat resembles a bronze dragon in appearance, but it has rust-colored skin and a grotesque, wrinkled look. Its wing membranes are clear and iridescent. Normally, this dragon will eat minerals, and its breath can turn metal into rusty garbage.
Styx Dragon: This dragon inhabits most areas of the lower planes (Hades, Abyss, Gehenna, Baator). They are most common in the River Styx, but can live in almost any fetid body of water. The styx dragon has a serpentine body that’s normally a light brown color, mottled with purple on the back. In addition, they also have a lure that they use to hunt prey. Their eyes are a lurid yellow color. They lack hind legs, and their wings are too small to allow them to fly. Thus, they are one of the few true dragons who cannot fly. They cannot move well on land either, so they are best safe in the water, where they are extremely deadly.
Tarterian Dragon: A denizen of the Tarterian Realm of Carceri, the tarterian dragon is the largest and strongest of the fiendish dragons. Its face and body are both long and skeletally gaunt. Their skin appears to hang over the body, and is shaded in bands of black and gray, with an occasional line of olive green in between. Their sharp claws and teeth are pure black, and their eyes glow with a feral green light. Though their wings appear to be torn and tattered, the dragon can still fly well. Living in Carceri, this dragon’s lair appears to be like a prison, and it loves to create that image wherever it goes. Normally, it will feed on the evil fiends and condemned souls that inhabit their plane, but won’t miss an opportunity to eat any other organism. Ironically, they are polite, well mannered, and soft-spoken.
Vampiric dragon: Although not always a fiend, this type of dragon is worth mentioning because it often appears in these planes of reality. There is no natural way to create a vampire dragon, that is to say normal vampires can not infect dragons. To become a Vampiric dragon the dragon itself needs to artificially give itself the means to become one. More often than not, a dragon will become a Vampiric dragon by accident when attempting to ascend to lichhood. Dragons become several times stronger physically and mentally when they transform into Vampiric dragons, also they heal at a hyper accelerated rate especially when feeding. They also gain the ability to hypnotize and dumbfound victims with just a stare, even other dragons. But this comes at a price; they, like most vampires, may not travel under sunlight, also they cannot move far from their lairs like a regular vampire cannot move far from its coffin, and they must constantly feed on the life’s blood of other living creatures or go insane from blood thirst. Vampiric dragons look like darker versions of what they once were and tend to become very sophisticated regardless of previous race.