From my gazetter (excuse the cut and paste):
Xyros is a foreign world full of strange and bizarre sights. Horses, lions, and bears are unfamiliar to its residents, as are most other forms of terrestrial life. The sky is green, the grass is orange, and the trees are both golden and throbbing. Monsters such as the dread lewartaan and the multi-winged peninga take the place of chimeras and wyverns, and the disembodied brain sars and floating contemplators are every bit as psionically dangerous as any mind flayer or aboleth. The oldest cities are made of crystal and unbreakable glass. Though they have stood for millennia, they appear as if but newly constructed.
Two suns - one cold, one bright and warm - illumine each of Xyros's long days, though they are the least of the planet's celestial boasts. Twenty-two crystalline moons occupy the crowded Xyrosian sky and glide across its emerald firmament in an intricate and never-ending ballet. Floating between them is Xyros's ring - the Ring - a flattened hoop of dust and crystal. Seen from the Hundred Cities of Xospahic, the Ring appears as a magnificent glowing arc across the sky, a band so thickly packed as to appear completely solid.
Plainly put, Xyros is not Earth, Scarn, or Toril.
Dwarves, elves, and gnomes do not make Xyrosian adventurers. Even humans are not found in great numbers here. Instead, the "standard" races of Xyros are unique to the milieu, including the bifurcated-limbed xaransu and the polyhedral-headed xos. Arcane wizards are unknown; psions and psychic warriors are the primary wielders of "magic" on Xyros. Priests pray to deities, but these deities do not grant spells, nor do they commune with their worshippers outside of demanding sacrifices to placate their perpetual hungers.
Xyros, in short, as a campaign setting, bears little familiarity to "standard" Dungeons and Dragons, and particularly so to pseudo-European backdrops like the Forgotten Realms, Greyhawk, or the Scarred Lands. Though medieval in culture and technology, Xospahic - the gazetteer focus of this book - is clearly the alien realm of an alien world.
- - - (end paste)
I tend to use the stats for regular animals and some monsters but just tweak them to look more "alien."