Hass was a resident of the Braxiatel Collection and a friend of Bernice Summerfield. Although originally a Martian, his timeline was rewritten during the activation of the history machine and his species switched to a Yesodi.
Hass arrived on the Collection after Irving Braxiatel had persuaded him to replace the beloved Mr Crofton, who had died during the Fifth Axis occupation. (AUDIO: Death and the Daleks, PROSE: ...Be Forgot) Hass was a famous gardener, a strange profession for a Martian, although he took his work extremely seriously. He struggled to make friends on the Collection, only really becoming close with Bernice Summerfield. (PROSE: A Life Worth Living) Back home, Hass' brother was a rising politician on Mars who was engaged in serious talks with Irving Braxiatel over his possession of several Martian artefacts.
In one possible timeline following the activation of the history machine, Hass' brother sent an army of clades to reclaim these artefacts and then nuclear warheads to destroy any evidence of the dishonour. (PROSE: Something Changed) In another, Hass was not even a Martian, but a Yesodi alien who pursued Bernice through the ruins of the Collection. (PROSE: The Ice Garden)
Following the Collection's return to normality Hass retained his Yesodi appearance. This new Hass continued his relationship with Bernice. He invited Peter and Bernice to come swimming with him in a pocket dimension where he was able to take off his pressure suit. (PROSE: Collected Works, AUDIO: Summer of Love)
With Ambassador Kothar's arrival on the Collection, Bev Tarrant had considered sending ambassadors to the Mimsphere to retain neutrality in the Draconian-Mim War. On Braxiatel's advice, she sent Hass and Joseph, as the environmental conditions of the Mimsphere would be hazardous to anyone else on the Collection. (AUDIO: The Judas Gift) Braxiatel's reasons for suggesting this change became apparent when Hass brought the war to an early closure by releasing months worth of stored radiation from his pressure suit, instantly destroying everyone on the Mimsphere. Although he felt guilty for this, he consoled himself with the belief he had done the right thing. (AUDIO: Freedom of Information)
He accompanied Braxiatel to Maximediras, here he saw how Braxiatel treated the colonist. He thought that Brax wanted him to do the action that stopped the Draconian-Mim War. (AUDIO: Resurrecting the Past) He helped Lianna Martin when she was sick and accompanied her to see Braxiatel when the Deindum gave him Joseph. Hass unleashed the radiation from his suit and wiped out all life on Maximediras. He came to love Lianna and hoped that he would meet her again after the timelines readjusted after the Deindum were defeated. (AUDIO: Escaping the Future)