Pillow Dragons are covered in enormous amounts of fur affectionately referred to as fluff. Despite their deceivingly large size, they can still fly even with such tiny wings because their bodies are remarkably light. Pillow Dragons have a habit of sleeping for up to eighteen hours a day, waking only in short bursts. During their few waking hours, they take the time to hunt for prey. Once a pillow dragon becomes an adult, its fur grows very slowly. Pillow dragon fur is used to make very expensive and valuable cloth known as “dragon cashmere.”

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Thomas Cat is always after the little crafty cheese dragon named Jerry Mouse. He'll often set up traps that end up backfiring, blowing up in his face, much to the amusement of the other dragons in the Raptor Clan. Sometimes he'll end up getting chased by the Brimstone Dragon known as Spike Bulldog as Jerry does everything in his power to get Thomas in trouble. Sometimes Thomas goes after other small creatures in the Clan, but ends up getting outwitted by them with the help of Jerry Mouse. He does sometimes fall in love with a female pillow dragon but gains competition by a frenemy of his.