First of all, why was the classroom so dark? Considering this was defense against the dark (dark haha) arts it made him a little nervous. What sort of thing would they be facing today? What was hiding in that darkness? Was it some sort of creature? Olly made sure he was standing close to an older student who knew what they were doing. He did not want to die today.

He thought about the question and raised his hand. "How about a crup? They look like a breed of muggle dog so if they saw one they'd think it was just a dog."