Dark green dragons, once they mature, appear to become an entirely different species. However, this isn’t true. Rather, they burrow underground and get nutrients from their vines. These vines are sometimes referred to as Dragon Grass. These dragons are very violent, and will use their vines to capture, kill, and eat anything that moves, as well as nearby plants. Luckily, their range is limited and they cannot use magic. Dark green dragons tend to be easy to spot since they usually kill all plants around them and thus are usually surrounded by a large clearing.

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.

Diego often laments that he still has been unable to remove a large tree in his vicinity, and becomes incredibly frustrated with prey that attempts to climb it towards safety, should they wander into his presence. He has been known to attempt using the tree to climb himself, pulling up with vines in pursuit of persistent prey, especially any "mocking birds," as he occasionally shouts. It's not clear whether he means birds of that species, or whether the birds mock him with their very presence.