Moonstone Dragons are named after the orb on their tails, which resembles the gem of the same name. They are nocturnal and gather energy through the absorption of moonlight with their orbs. They seem to glow with a lunar light and are a very gentle breed, feeding off of plants and the moons’ power.

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.

Deep Thinker is almost obsessed with puzzles of all kinds. He cannot get enough of them. While his brother sighs wistfully at the elegant words Sir Scribe can write, Deep Thinker actually put the paper dragon to use. Once he realized that Whitey would give Kanaye a list of things he wanted and she would buy them for him, Deep Thinker started pestering Sir Scribe to write lists for him as well. Now he has boxes and books filled entirely with puzzles, every logical dragon's dream. Once, his brother told him some foolish thing about beauty and it hadn't taken a second's thought before he'd whacked him over the head with a book of mazes and told him to "Stick with reality".