Belkan man, friend of Teyla Emmagan and the Athosian people. He was present during Teyla's negotiations with Hendon, likely at her request. He knew the Hendon well enough to know better than to threaten him by forcing his hand, for it would only make matters worse during following negotiations.
Mattas was responsible for serving drinks to Hendon and Teyla's party while she was attempting to negotiate for a particular flax seed. He may have also had an official presence at the negotiating table, as Teyla was very familiar with him.
Trinity - Mattas serves drinks for the negotiation party and later tells Teyla Emmagan of a Satedan who settled on his world.