Joseph

Joseph is a young dragon. He is first seen in the fourth episode of Season 1 when the Eleventh Doctor and Merlin order Tyrant to bring him over so that he can cook the food for their barbecue. Unfortunately, Joseph is captured by a group of Weeping Angels. The Doctor, Merlin, Tyrant and Claire go on a crusade to save him from the Weeping Angels. After the Doctor, Merlin and Claire are surrounded by the Weeping Angels, Tyrant manages to save Joseph, the Doctor, Merlin and Claire from the Weeping Angels by smashing them. Joseph is then seen happily cooking the food for everyone at their barbecue.

In Season 2, Joseph appears in the fourth episode, helping the medieval inhabitants to stave off the forces of Davros. He proves to be their most useful asset with his fire breath, until Ood Sigma shows up. When his friends start admiring Ood Sigma, Joseph feels that he is being replaced. However, he helps the Eleventh Doctor to rescue Ood Sigma from Rassilon.

In Season 3, Joseph is among the medieval inhabitants who are captured and impersonated by the Zygons. The Doctors and company try to save him and the others, but they too wind up getting captured. Luckily, the War Doctor comes in to save the day. He rescues all the Zygons' prisoners, destroys their spaceship and manages to trick the Skarasen into devouring Bortog, the warlord of the Zygons. Joseph is last seen tearfully waving the Doctors goodbye.