Habris was the captain of the guard in the Hydrax where he served the Three Who Rule.
Habris was charged with making the selection for the Three. Despite his friendship with Ivo, the leader of the peasants, Habris selected Ivo's son Karl. He tried to help Karl become a guard, but the Three made him a sacrifice instead. Habris was also charged with reporting the quality of harvests to the tower.
He mistook the Fourth Doctor and Romana II for lords based on their appearance. When Ivo and the peasants attacked the castle, he informed Aukon, who told him that as a guard, it was his duty to die. Habris was killed by Ivo in vengeance for his son. (TV: State of Decay)
