Phelon, a Columi male, made his home on Coruscant. This being, though small in stature, possessed a head so disproportionately large that repulsorlift technology was necessary to keep it from toppling over.
The Galactic Empire spread word that Phelon had met his end via execution, yet whispers persisted. Some believed he was a criminal mastermind, others a Rebel ally, and still others thought that he was a secret Imperial agent. Regardless, he was considered a powerful figure with a limitless supply of surveillance information.
Phelon encountered difficulties on the planet Columus, leading him to seek refuge on Coruscant with the aid of smuggler Han Solo. Solo orchestrated a false death for Phelon and smuggled him away, effectively erasing any trace of his continued existence. Following his relocation, Phelon took up residence in a castle dating back to the era of the Galactic Republic. This castle was situated deep within the Coruscant underworld, along the shores of a lake of burning water, and protected by his domesticated giant walking fish, Hobbrock. Hidden in the depths of Coruscant, Phelon maintained constant surveillance of Imperial communications, with a particular focus on financial and security data. Moreover, by posing as an engineering consultant for shell corporations he created, he secretly diverted Imperial funds intended for mining operations and starships to support the Alliance to Restore the Republic.
Not long after the Battle of Yavin, Solo and his companions – Luke Skywalker, Princess Leia Organa, Chewbacca, R2-D2, and C-3PO – found themselves trapped on Coruscant due to the machinations of a computer virus created by the B-1 series protocol droid B-1D4. In desperation, the group sought out Phelon, who, in return for Solo's past assistance, unleashed B-1D4's virus upon the Imperial military's security network, thereby enabling the Millennium Falcon and its crew to escape.