The dragon hadn't been sure he was going to be a dragon for the masque until two weeks ago when a package arrived during breakfast. As his habit was, he took the package, unopened, to his dorm and when he opened it, he was pleased he'd waited. A note from his father explained that he'd been in Diagon running some errands and had come across this costume for a decent price and that, if he weren't inclined to use it, to give it to a friend.

Surprised by his father's generosity, he had pulled out the costume. It consisted of a body suit with black iridescent scales and a long tail trailing off the back. A masque fit over the top half of his face with a snout of about a foot long sticking from it. There was a vial of potioned creme for him to spread upon his face, neck, and hands that temporarily turned the skin into the look of iridescent scales, much like the bodysuit.

As to the breed of dragon, it wasn't truly a breed. It was merely 'a black dragon'.  A black, iridescent dragon.

Entering into the masque, he tilted his head up to look at the starry sky with the full moon and then turned his attention towards the smells of food, his stomach grumbling in response as he made his way in that direction.