A huge moon, with a three-coned volcano which can be seen from the planet when it erupts and is taken for an omen. The planet, smaller than the moon, orbits it, and the planet in turn is orbited by a very small but very hot and bright ball of flame.
The ochre sands stretch for miles around. Something kicks up the dust. It's a yak. A desert-yak. It ambles slowly, nuzzling the ground for the low-growing shrubs. The ranger freezes. "Stay very still," he warns. "Don't move at all."
"What is it?" you ask, breathlessly.
"It's the most dangerous creature in the whole Ocadian desert. And it's about to eat that yak..."