Pit fiend

The most terrible baatezu of the Nine Hells, pit fiends appear to be giant, winged humanoids, very much like gargoyles in appearance, with huge wings that wrap around their bodies for defense. Pit fiends' fangs are large and drip with a vile, green liquid. Their bodies are red and scaly, often emitting flames when they are angered or excited. In the rare situations they choose to communicate, they use telepathy.

Note: Pit fiends originally appeared in this form in the 2nd Edition Monstrous Manual for the AD&D game from TSR. Their use here is for the purposes of providing context for the campaign only.