Zak was a Clone Captain in the Republic Navy during the Clone Wars, a galactic conflict fought between the Republic and the Confederacy of Independent Systems. Like their fellow clone troopers, they had been cloned on the planet Kamino from the bounty hunter Jango Fett.
During the war, Zak was stationed on a Consular-class cruiser that was tasked with delivering Jedi Grand Master Yoda to Rugosa, where the Jedi Master was to meet with King Katuunko of Toydaria. However, the starship was attacked by the Confederacy, which sought its own alliance with the King. While Zak wanted to get Yoda to safety, the Jedi General and a trio of diplomatic service clone troopers landed on the moon in an escape pod. Eventually, Yoda and the troops defeated a force of battle droids and united with Katuunko, who agreed to building a Republic base on his world.
Zak first appeared in "Ambush," the first episode of the animated television series Star Wars: The Clone Wars' first season, which originally aired on October 3, 2008, where he was voiced by Dee Bradley Baker. Their name and rank of captain were identified in the foreign credits of the episode on Disney+.