Gilean was a male Muun who served as Boba Fett's banker, handling his financial and bounty assignments. When a bounty was offered for Connor Freeman, a Human who owed credits to a powerful crimelord named Tayand, Gilean raised it to Fett's attention, thinking that the bounty hunter would recognize the individual. But when Fett displayed no knowledge of Freeman, Gilean tried to steer the conversation another way, deeming it illegal to disclose personal information. Fett threatened Gilean, who then told Fett that Freeman recently emptied an inheritance fund set up for him by Fett's father, Jango Fett. Eager to know what Freeman's connection to his father, Fett accepted the job despite the low pay.
Aside from being a banker, Gilean was also a businessman. Fett himself was of the opinion that Gilean was very good at both of his professions.