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.

Diona Tanglevine is Dandil's greatest rival for the attention of Royal Menagerie visitors, and the two will often compete to see who can get the most shrieks from spectators.  She's the most aggressive of the dragons in the Dragonvine Gardens, and is always trying to pick fights with her neighbors.  The Dragonvine Garden dragonkeepers are especially wary of Diona, since she will attack any human who comes near her, in hopes of discovering some flaw in their magical shielding.  If she ever did hurt a keeper, she'd be released straight back into the wild, but Diona keeps trying to attack them despite the risk.