Zak Saturday is the main character of The Secret Saturdays. He is the son of Doc and Drew Saturday, nephew of Doyle, and brother to Fiskerton, Zon, and Komodo. Together with his family of Secret Scientists, he hunts and saves cryptids, creatures of myth with extraordinary abilities that aren't scientifically proven, like Bigfoot or the Chupacabra. In the technical sense of the term he is a hero, but he is also Kur, the source of ultimate evil, with the ability to control all cryptids, and he has been known to be in cahoots with Argost to help him study his powers. However, he wishes to do good, so his future is a hard one to read.
In FusionFall, Zak originally appeared as a preview NPC for the Birthday Bash, but was later added permanently along with Fiskerton at Mount Blackhead.
In "Cryptid Crisis (Part 1 of 3)," Zak asks the player to report to Drew and ask her about any recent cryptid sightings. Drew explains that while her cryptid scanners are detecting them everywhere, she can't find any cryptids herself. Zak suspects it has something to do with the Fusion monsters.
In the Fusionfall: The Animated Seriesepisode (Comedy Central continuity) "Sweet Jailbreak," Zak and Pairie (a member of the Fuse-Busters) share their first kiss.
In the episode "When The Boys Collide," Zak confirms that he is a nerd.