Princess of Amathar is a science fiction novel. What would a science fiction novel be without aliens. The story takes place in a hollow world which was long ago stocked with life from other planets. The primary races in the story are:
Amatharians: Humans with blue skin.
Zoasians: Reptilians with snake-like faces and massive bodies, nearly as wide as they are tall.
Malagor: Furry aliens with some ape-like and some dog-like traits.
Pell: Large, intelligent spiders.
Kartags: Semi-intelligent subterranian rat creatures.
Bloobnoob: Slimy amphibians.