From Ardrana

Githyanki are an ancient race descended from Humans. They dwell upon the Astral Plane but will often leave that plane to make war on other races. They are engaged in a lengthy war with the githzerai.

Githyanki are strongly humanoid in appearance. They are approximately of human height but tend to be much more gaunt and long of limb. They have rough, yellow skin and gleaming black eyes that instantly betray their inhumanness. Like many demihuman races, their ears have sharp points and are serrated at the back. Dress for the githyanki is always an elaborate affair. Their baroque armor and weapons of war are decorated with feathers, beads, and precious metals and gems.

Githyanki often make appearances in Ardrana. At some point, a band of githyanki were thought to have obtained Black Razor following the death of the wizard Bargle, but that has not been confirmed. They are known to have a stronghold on an island off the coast of Faxanadu, from which they occasionally launch raiding parties seeking magical items.

Note: Githyanki 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.