Zak served as a Clone Captain within the Republic Navy throughout the Clone Wars. This galactic conflict saw the Republic in battle against the Confederacy of Independent Systems. Like the other clone troopers, Zak and his brethren were cloned on the planet of Kamino using the genetic template of the bounty hunter known as Jango Fett.
During the Clone Wars, Zak found himself stationed aboard a Consular-class cruiser. The cruiser's mission was to deliver Jedi Grand Master Yoda to the planet Rugosa. Yoda was scheduled to meet with King Katuunko of Toydaria. However, the Confederacy launched an attack on the starship, aiming to secure their own alliance with the King. Despite Zak's desire to ensure Yoda's safety, the Jedi General, along with three diplomatic service clone troopers, made their way to the moon via an escape pod. Ultimately, Yoda and the troops were successful in defeating a force of battle droids and joined Katuunko, who then agreed to the construction of a Republic base on his planet.
Zak's initial appearance was in "Ambush," which was the debut episode of the animated series Star Wars: The Clone Wars' first season. It was originally broadcast on October 3, 2008. Dee Bradley Baker provided the character's voice. The name and rank of captain were confirmed in the international credits for the episode on Disney+.