Pa'u Zotoh Zhaan is a Delvian, a blue, spiritual, humanoid plant species, and a Pa'u (priestess) in their religious order. Zhaan was imprisoned aboard Moya for the assassination of the leader of the Delvian government and her lover, Bitaal. Bitaal refused to step down as leader of the Delvian people when his tenure was over. He, along with other conservative Pa'us, hired the Peacekeepers for "external security." There was a political crackdown and it is implied that some atrocities occurred under Bitaal's rule. Zhaan, while in Unity (an erotic, if not entirely sexual, activity unique to Delvians) with Bitaal, killed him and drove herself insane in the process. It is unclear whether Zhaan was a member of a terrorist group or whether she acted alone. It is clear, however, that Zhaan was courted by a violent revolutionary organization of Pa'us on a planet they encountered in the Uncharted Territories. She has also been an anarchist, and like other trained Delvians, Zhaan has several empathic and telepathic abilities which she cultivated to Pa'u level during her time in prison on Moya, although she was forced to channel these abilities to cause harm during the crew's first confrontation with the powerful Maldis in order to stop him and save the currently-imprisoned Crichton. She is also skilled in medicine and other related sciences. During her time aboard Moya, she is often seen making drugs and explosives in her workshop to assist her shipmates.
As a Pa'u, Zhaan's spiritual abilities significantly improve upon achieving a new level. When first introduced, Zhaan is a level nine Pa'u, with the ability to lessen the pain of others by taking some portion of it into herself. Later with Crichton's help, she gains a level, becoming a level ten Pa'u and gaining the ability to protect others from psychic attack with her own mind. She shows that for short periods of time she can make herself invisible, although it is not stated whether or not this is only possible when surrounded by foliage.
Zhaan saved the seemingly dead Aeryn Sun, and in the process became critically ill herself. While the crew are searching for a planet with the right conditions for Zhaan to heal, John Crichton diverts Moya to investigate a wormhole instead, where the Leviathan collides with another spacecraft. In order to save Moya and her crew, Zhaan sacrifices herself by piloting the other craft away before it is destroyed.