Leaf Dragons were colossal in size, towering over humans. Their bodies were several metres long and possessed an overall greyish colour and scaly hide. They were bioluminescent, with naturally occurring cyan light showing between their scales, inside their mouths and even on the tips of tendrils that were located on their foreheads and tails. This suggested they were native to an aquatic planet, fins and gills being present. However they were also amphibious, being able to survive in Earth's atmosphere.
Leaf Dragons fed on the blood of their prey and were carnivorous.
Leaf Dragons appeared to be able to travel through the tears in space and time at will. The tear would automatically snap shut behind them.
Due to their massive size, they were incredibly strong and tough, able to easily overpower and subdue their prey.
Leaf Dragons killed their prey by skinning them alive in a matter of seconds. They would then leave the skin behind and drag the body back to another location to feed on the blood.
They were also fearsome predators. Despite their massive size, they could move very stealthily while stalking their prey and ambush them in a surprise attack.
They were quite intelligent and could even speak human English and had concepts such as love.
Leaf Dragons could imprint themselves onto the skin of another being. This made the host stronger than normal but left the Leaf Dragon trapped with no way of escape. They needed to be fed or they would die of starvation. The Leaf Dragons themselves did not know how to solve this problem.
A pair of Leaf Dragons found their way to Coal Hill Academy through a rip in space-time in the hallway. After the female dragon was imprinted on the body of Coach Dawson, the male dragon murdered at his behest. (TV: The Coach with the Dragon Tattoo)