An associate of the mad Dr. Evason, Ponda Babba assisted him in his schemes.  During a run in with Obi-wan Kenobi at the Mos Eisley Cantina he lost his arm.  Evason preformed an experiment to transport Ponda's essence into a Aqualish dignitary in an attempt to regain his lost limb.   The experiment was a success but it transferred the dignitary instead, very angry at having an inferior body and outraged at the Doctor because of his illegal experiments.