Vampire dragons are members of the undead. They sustain themselves by drinking the blood of others. It is said that they are only "alive" at night, and seem dead or asleep during the day, as they cannot endure sunlight for long periods of time. Vampire dragons can only reproduce by changing the eggs of other dragons, puncturing the shell with their fangs and injecting venom that kills the baby inside.

Ensconced in a tight corner of pillaring rocks, Emd Dem Dem's rotting egg sat. The foul odour was enough to put any dragon-tender or dragon off.

Although how he came into being is a complete mystery, Emd Dem Dem somehow found his way to 42 where he refused to decamp and instead occupied a good portion of rocky terrain. He has never been seen again. To young hatchlings, he's considered a myth and a good story told by adult dragons.