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.
DeathVine the 3rd isn't really as ominous as his name suggests. He's just a bit of a bully, tripping other dragons with his vines, popping out of the ground and scaring passersby, or just taunting others. Otherwise, he sleeps most of the day and eats mice or other small rodents that try to run past.