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.

When Lorraine first found Diggory's egg, she knew that there would be something odd about him.  Flowers and grasses appeared wherever she set it down, even in caves with no sun or dirt to speak of.  Her guess was confirmed when he hatched, so covered in camouflaging vines and weeds that she wasn't sure at first that he was even a dragon, but the truth of his nature was only guessed at before the day he disappeared.  The usual mass of ever-growing vines went missing from the caves.  A mountain-wide search eventually revealed a strange patch of carnivorous plant life, in a clearing by itself, but they still didn't know it was Diggory until Minalrito was attacked by it.  Ever since the flames that followed, Diggory has tried in vain to trick the red dragon into sleeping on soft dirt, which a dark green dragon can burrow under and attack through safely.  He has yet to succeed.