Dark Sun: The Pristine Tower

"The effect of this cannot be understood without being there. The beauty of it cannot be understood, either, and when you see beauty in desolation it changes something inside you."

- Annihilation, Jeff VanderMeer

The Pristine Tower is a mysterious structure in the deserts of Athas. It is first mentioned in Denning's novel Amber Enchantress, but later figures into an adventure Dregoth Ascending. I'm going to ignore for this post what the Tower is and the roll it plays in the history of Athas, as that's something one might or might not want to use in there own campaign, but I think the Pristine Tower as enough interesting things about it, it's worth including even without the backstory.

Tower is at least mutagenic, perhaps reality-warping. While the novel is disappointingly bland in the description of its environs, I think you can easily borrow strange details from Annihilation (the film or the novel) or perhaps Roadside Picnic, though with more emphasis on the biological rather than the technological.

We are told that anything that bleeds within the zone around the tower (perhaps anything that is injury) begins getting remade as some other creature. This is the source of the "new races" of Athas--like the nikaal or the humanoid baazrag. Also it creates unique mutations like Magnus, who was born of elves but looks nothing like one, and the half-human, half-insectoid Prince Dhojakt.

The fact that mutation only seems to occur after bleeding (or perhaps injury) is interesting. Is the Tower exerting some sort out of control healing field? Or is it trying to produce lifeforms better suited to survival on Athas and just needs better access to genetic material than intact skin provides? Or perhaps it's just a mutagen changing everything in range slowly, and natural healing just gives a more rapid avenue for that process?

In the novel, the area around the Tower is inhabited by rather normal creatures, but I think the chimeric creatures of the Annihilation film are more appropriate. You could also use my Random Zonal Aberrations tables. Of course always keep in mind that "weird for Earth" isn't necessarily weird for Athas.