D&D has always been fatasy-genre fanfic mashup awesomeness when you take the whole thing into account. Even Gary shmushed together wargames and Tolkein and the Elric saga and Greek myth and cheap plastic chinese toys...there is no semblance of genre purity in this game.
So... the 2e Monstrous Manual?
Ecology: Kirre are a favorite game of many hunting tribes of races who live in the forests of Athas. The meat from kirres is some of the finest on all of Athas, and it is sought after by many. Aside from a source of food, the kirre also has other uses when killed. The creature's horns can be cut off and used as spear heads; in some cases, they can be carved into ornate daggers. Also, the tail of a kirre has a sharp, bone spike at its end that can be fashioned into either an arrow head or a dart.
As noted, marilith are the strategists of the Blood War. They are in charge of devising all tactics to be used during the battles and coordinate the activities of all true tanar'ri (save the mighty balors, of course). Due to the chaotic nature of the tanar'ri, it is not really possible to coordinate their activities, but the marilith are charged with it, nonetheless.
Habitat/Society: Death knights are former good warriors who were judged by the gods to be guilty of unforgivable crimes, such as murder or treason. (For instance, Krynn's Lord Soth, the most famous of all death knights, murdered his wife so that he could continue an affair with an elfmaid.) Death knights are cursed to remain in their former domains, usually castles or other strongholds. They are further condemned to remember their crime in song on any night when the moon is full; few sounds are as terrifying as a death knight's chilling melody echoing through the moonlit countryside. Death knights are likely to attack any creature that interrupts their songs or trespasses in their domains.
Like the other species of lycanthrope found in Ravenloft, two varieties of werebat exist -- natural (or true) and infected. True werebats are those creatures who have been born to werebat parents. The parents may be either true or infected werebats themselves, but the offspring of any two werebats is a true werebat. In those rare cases when a child is born with one werebat and one human parent, there is a 50% chance that it will be a true werebat and a 25% chance that it will be an infected werebat.
Dark nagas tend to be loners, but can form stable family groups of two or three; they are bisexual, and give birth to a squirming mass of many wormlike young which they promptly abandon to fend for themselves. Intelligent enough to know they can prevail against few creatures in the Realms alone, dark nagas work with other evil creatures, such as orcs, hobgoblins, drow, phaerimm, beholders, and the like. [...]
Every adult member of this race possesses the following magical abilities, each usable three times a day:
astral spell, plane shift, and
ESP. All function as the spell of the same name (as cast by the lowest-level caster possible). These inherent abilities also enable the pirates to pilot ships with series helms. These abilities function only in wildspace, not in the phlogiston.
I guess it worked for 2nd edition...