Doroa is the second eldest child of the King and Queen of Psycadon, younger sister of Jumbo and older sister of Saran. Following the death of her father and the believed death of her mum, Doroa took on the role of Queen of Psycadon
Unlike most Psydonian's, Doroa isn't that keen on violence but hides this fact from her parents with only Saran and Jumbo knowing. Although they consider the Time Lords to not be their friends, Doroa didn't reveal that she knew the Doctor was on Psycadon.
Doroa later reappeared alongside Saran in Petrification, assisting their family in an attack on the London Underground. Doroa assisted with bringing humans killed or petrified by the Basilisk to their headquarters, using their energy to increase theirs.
They later assisted Jumbo with Iris who had been petrified but were soon captured by UNIT soldiers. The Doctor spoke up for them and alongside Jumbo and Saran, came up with a plan to stop their family. Their plan resulted in their father being blown up, an attack which destroyed most of the Underground.
Believing their mother to have been killed in the attack, Doroa returned to Psycadon and became the new Queen. Unbeknownst to her, their mother was still alive.
Behind the scenes
Doroa along with Saran were planned as one-off characters, only appearing in The Traitor but their popularity with the readers has lead to a second appearance being written featuring them.