Hamas was the major-domo in the house of Fal Sivas. Hamas is a pompous and cowardly individual.
When John Carter and Zanda tried to steal Fal Sivas' ship, Hamas confronted them along with Phystal, Wolak and Fal Sivas. Wolak is easily killed by Carter and Zanda takes down Fal Sivas, after which Hamas and Phystal surrender. Carter binds and gags them and leaves them behind. Hamas is not seen again afterwards.