Gryyzak was a male Wookiee Senator representing his people in the Galactic Republic following the signing of the Zakuul–Republic treaty. His gender is male.
Back in 3631 BBY, Hylo Visz, a friend of Gryyzak, extended an invitation for him to join forces with the Anti-Zakuul Alliance. However, communication with Hylo was lost within the Alderaan system. Gryyzak was scheduled to meet with a Talz senator at the Parliament on Alderaan. This meeting was disrupted by an assault led by Broonmark, a ferocious Talz, which forced both senators to seek protection. Broonmark pursued the senators and their protectors, ultimately eliminating all but Gryyzak. Just as Broonmark was about to kill Gryyzak, the Alliance Commander, dispatched by Hylo Visz to check on Gryyzak's well-being, intervened. Broonmark stated that he wanted to murder the Wookiee due to his peacekeeping efforts with the Talz, which Broonmark considered as depriving the Talz of their true nature. The Alliance Commander refused to permit the killing of an innocent, leading Broonmark to attack. After being defeated, Broonmark refused to be spared. Gryyzak then expressed his gratitude to his savior and offered his support to the Alliance.
Gryyzak makes an appearance in Star Wars: The Old Republic: Knights of the Fallen Empire during the Broonmark Alliance alert mission. Broonmark can only be recruited by choosing a dark side option that allows him to kill Gryyzak; all attempts to negotiate with Broonmark will fail as long as the Wookiee is alive. The Sith Warrior is an exception, as they can prevent Broonmark from killing the Senator. The Wrath can then recruit Broonmark as a companion and secure Gryyzak's assistance in the fight against Arcann. If Gryyzak is killed during this encounter and Broonmark is recruited, Hylo will voice her displeasure with how the mission turned out and promise to keep Broonmark away from her and her smugglers on Odessen.