When an explosion awakens young Ruddy in his dungeon bedroom in Castle Chaos, he escapes to the top of the tallest tower and tries to flee by transforming into his true form: a fire-breathing dragon. Instead, he's captured by the Royal Watch and registered for classes at the Royal Academy for Creature Habilitation, a juvenile hall for young monsters.
Under the watchful eye of his undead principal, Mr. Mortis, Ruddy must deal with his werewolf and goblin roommates and contend with a pair of troll-orc bullies bent on showing him who's boss at this school. But it all gets worse when a famed monster hunter turns up dead and the dragon kid is accused of his murder.
Ruddy and his new friends must work fast to clear his name. Otherwise, Abbot Pious will declare him guilty, close down the school, and put him to death!