A wide variety of animals live in the Throne of Glass universe. Many of these animals exist in the real world, but many others are fictitious.
Several real-world animals have been encountered in the Throne of Glass universe.
- Dogs. The King of Adarlan kept many dogs in expansive kennels at the glass castle. His son Dorian spent a great deal of time in these kennels caring for the dogs. As a Yulemas gift, Dorian presented Celaena with a puppy whose life she had begged him to spare (the pup had an odd temperament, and Dorian had planned to euthanize her); Celaena named her Fleetfoot.
- Wolves. Fenrys's and Conall's animal forms are wolves; Aedion Ashryver's sobriquet is the "Wolf of the North"; Celaena wonders if Fleetfoot might be part wolf.
- Cats (house cats).Lysandra revealed her shape-shifting abilities to her mother by transforming into a hissing tabby cat after being startled. Aelin also said that Rowan was "no better than a house cat", indicating that cats are domesticated and kept as pets in the Throne of Glass universe.
- Mountain lions.
- Crows.Lysandra briefly changed into a crow while journeying to Terrasen with Aelin's court.
- Hawks.A white-tailed hawk (later revealed to be Rowan in his animal form) perched on a chimney in Varese.
- Eagles. Chaol's sword had an eagle-shaped pommel.
- Pheasants. Pheasant is often served at feasts.
- Chickens. Chicken is a common food in the Throne of Glass universe.
- Bats. Celaena studied bats to absorb their silence and focus under the instruction of the Mute Master.
- Rats. After Celaena killed Yrene's attackers behind the White Pig in Innish, the rats gathered around the corpses to devour the flesh.
- Rabbits. While under the tutelage of the Mute Master, Celaena spent considerable time observing jackrabbits to learn their stillness, speed, dexterity, and acute senses.
- Squirrels. Chaol pointed out that the Endovier guards could shoot a squirrel from two hundred paces away.
- Beetles. Desert beetles were among the animals the Mute Master made Celaena study during her training with him.
- Horses. As in the real world, horses in the Throne of Glass universe serve as mounts and pack animals. People ride them or use them to pull carriages, carts, and the like.
- Bears. Aedion mentions that there are bears in the Staghorn Mountains.
- Even-toed ungulates:
There are also several fantastic animals in the Throne of Glass universe. Some of these animals possess magical powers or even the power of speech.
- Ghost leopards.
- Asterion horses. Asterion horses are prized for their beauty and endurance. As such, they command high prices in the market; therefore, only nobles and other wealthy citizens can afford to purchase them. Their pedigrees are traced through the females, and mares are more valuable than stallions.
- Firebirds. Emrys told a story involving a firebird. Whether or not they are real in the Throne of Glass universe is unknown.
- Stygian spiders.
- Skinwalkers. Aelin and Rowan were attacked and pursued by a pack of skinwalkers in Heir of Fire.