Duncan's full name is Duncan Xeres Absalom Wu Fan Cassius Draco Draconus Quetzelcoatl Gondwana Mjarl Khan Belloc-Rosenblatt Jr. He is a half-human and half-dragon hybrid. His mother Margaret Rosenblatt is human and his father, Belloc is a three hundred foot tall dragon and is the King of all Monsters/Dragons. Both his parents are divorced and while Margaret wants Duncan to lead a normal life such as getting good grades and getting in to college. Belloc hopes that Duncan will one day follow in his foot steps, destroying, conquering and becoming the next king; but due to his life Duncan is an outcast and often has to move around a lot although he has come to terms with that.
Duncan has a hard time trying to fit in at his new school. He has to deal with a school bully named Troy and his school principal. However he was able to confine in other outcast such as himself named Ken Rogers. Duncan then goes to train with his father for the weekend were he is escorted to by the Head of the United Nations, Special Operations Strikeforce; Colonel Booshwa Barnes who does so regualry. At school Troy tries to get Duncan in trouble and he hides a gun and tries to frame Duncan for having it. This causes Duncan to worry about whether his place is really with humans, but he soon forgets about that when he goes home to find it destroyed and his mother missing. Duncan is soon able to find his mother and the monster that captured her. Duncan and the beast battle, which ends with the monster being badly burned by Duncan’s flame. However Belloc arrives and finishes the monster off by stabbing him with his tail. Duncan realizes that it was Belloc who arranged the whole thing and Duncan threatens his father’s life, but this causes Belloc to show pride in Duncan by saying "That's my boy."
Later Duncan goes on an field trip to London with his class and a Spanish teacher named Mr.M. Unbeknown to Duncan, he is both an S.O.S agent and a descendant of a Spanish village that his father destroyed centuries ago. The survivors built a suit of armor called the Iron Saint created to destroy Belloc. Duncan becomes aware of the suits past and that it has come back to life. In reality the suit is being worn by Mr. M wanting revenge. However due to the fact Duncan is half human the suit is destroyed when it touches him, as it was not meant to be used on humans.
Duncan would later join the short lived group the Pact fighting their foes including his father Belloc, space aliens, lava monsters and Doc Seismic.
As a result of his half dragon heritage, Duncan possesses superhuman strength, reflexes, durability, hearing, agility, and endurance. His body is covered in scales that are highly resistant to harm. He has bat-like wings on his back that allows him to fly. Like his name suggests, Duncan can breath fire, that he can manipulate in other ways as well. One of the ways he can do this is he can hold the generated flame with hands and throw it. Duncan can also utilize retractable claws, that he can use to cause great damage.
The movie Firebreather was aired on Cartoon Network on November 24 2010 his father Belloc returns wanting his son Duncan to take over the throne meanwhile his mother has different plans for him he seems to always getting in trouble at school and moving from school to school .