Blacktip Dragons are a small, shore-dwelling breed that tend to nest on sheer ocean side cliffs. They live in groups under a dominant female, who prevents her subordinates from breeding. During the mating season, a group of Blacktips can be very noisy and smelly indeed; males produce a distinctive musky odor and loud, low-pitched honking noises in an attempt to woo the alpha female.

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.

Castos enjoys jumping off cliffs, gliding into the ocean gracefully. She often allows humans to ride on her back as she makes these jumps, but only after they treat her with fried fish. She's becoming awfully plump from this. She occasionally travels to see exotic lands, often flirting with dragons there. For instance, she once had a short-lived romance in the desert with an Albino Dragon named Ra Horus Anubis. She produced an egg with him named Nile Castus Anubis, who was born with brown markings where his black tips would be. She didn't stay to raise him. Although she often writes him letters and sends him scrolls, she's not interested in being a mother, and leaves raising Nile to his father. She has countless other eggs.