(in response to Grognaria's call to arms)
Tell us about your orcs... well orcs are made by giants. Powerful giant shamans know how to turn the livestock that pesky humans keep into beast-men. A good way to keep the frontiersmen away. They do the same with boars that men chase, dogs that bay at the edges of their villages... I pictured the orcs as mostly simian featured with jutting jaws and big bottom teeth (I think from my favorite orc lead figure of the day).
It's been a very long time since I played, but back then I had an elaborate magical evolutionary tree. In short, when the world began, there were Dragons, the Fae, and Giants. Assume the usual "ages pass in cycles of animosity and lassitude, mankind rising unnoticed by the Big 3", as they were in a kind of a magical arms-race of evolution. At this point, another player gets involved in this life creation racket: wizards.
So the only race that wasn't created by magic is the humans. I might try to dig through old notes to find the ridiculously complicated causal chain of life... I remember that dragons made dwarves & kobalds from rocks, fae made goblins & elves from fairy dust(?), giants made orcs & gnomes from animals.
The arms race side of it was this: A dragon makes a dwarf. Dwarf meets a Fairy and gets changed to a brownie. Or dragon made a kobald instead. The kobald meets the wrong cloud giant and is transformed into a griffon... Each of the 'client races' could be further transformed by the opposing 'creator races'.
I think I was riffing off of TITAN - in which your pieces could muster recruits based on the terrain of the space they occupied. I liked the wizards too, but they kinda had the shit end of the stick. The old races had much latitude in what they could do to a wizard. Unseen servants, intelligent magic items, familiars, permanent spells - these things could be transformed into esoteric creatures (say, save or fire giant turns your ring of spell storing into a salamander). It meant that magic users would have to divest themselves of much of their adjuncts and accoutrements when facing the magic using varieties of these older races.
It was interesting - way too much trouble to go through to contextualize the presence of the minotaur(giant curse), otyugh (fairy curse), and ogre magi(dragon curse). I'll dig around and see if I can't come up with the tables I made for this a long time ago...