Tak was a Halosian lord, he commanded the ship Halos-1. Tak was determined to move, or "evolve" through the ranks of his society according to the Halosian Code. It was to this end that he attacked Talyn -- despite Bialar Crais' insistance that they were peaceful travelers. Talyn, in turn, attacked the Halosian ship -- easily defeating them and killing 30 of its crew members. Talyn spared the ship and departed, leaving Tak to try to recover from this disastrous failure with the aid of his subordinate Yoz.
When Moya approached, Tak believed Talyn had merely been an advance recon ship for this larger vessel. However, when Pa'u Zotoh Zhaan boarded his vessel under peaceful pretenses, and was taken captive, he learned that Moya was unarmed. He believed this made her defenseless and an easy target -- so he fired his weapons. Moya was able to activate her defense screen and protected herself.
Seeking a way around the protection, Tak boarded Moya -- claiming he needed to see for himself that they were not a threat to him. In the midst of his tour of the ship, he became ill and violently vomited onto one of Moya's systems. The vomit, in truth, was an acid that began shorting out Moya's systems.
Upon returning to his ship, he attempted to fire again -- but Moya's crew had quickly repaired the damage and raised the defense screen once more. At this point, however, Yoz had become convinced of Tak's failure. She killed him and took his place -- evolving according to the Code that Tak had dedicated his life to pursuing.
Source[]
Tak is derived from Farscape.