|Series||The Secret Saturdays|
|Voiced by||Sam Lerner|
|“||Everyone has secrets. My family just has bigger ones...||”|
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.
Later on, after the series ended, Zak and his family appeared in an episode of Ben 10: Omniverse, confirming that both shows are within the same universe, and that Zak already knows about Ben because of the reports in the news. In this appearance, Zak appears to have grown up more and is now a teenager like Ben. The Saturdays teamed up with Ben and Rook to foil the plans of Dr. Animo and the revived V.V. Argost.
FusionFallIn FusionFall, Zak originally appeared as a preview NPC for the Birthday Bash, but was later added permanently along with Fiskerton at Mount Blackhead. If addressed, he may ask if the player has seen Komodo. He also randomly wonders aloud if Doyle has made it to the Darklands yet. Zak took part in the Mother's Day Event by participating in a mission given to the player by a KND SKWID. He seems to attract attention from the Fusions near the border of Twisted Forest, but lately there has been no sign of them bothering him. He sends the hero to investigate the Granite Grabbers and Creeper Kings. After surveying them, Zak discovers a Fusion lair near the hero's position and sends the hero to enter it and check on the Fusion inside. When inside the hero is attacked by multiple Creeper Kings and is forced to stand them off. After defeating the Creeper Kings, the hero discovers that Fuse created a Fusion Zak to control the Fusions in the area. Fusion Zak attacks the hero focused on destroying him, but in the end the hero defeats Zak's Fusion counterpart.
- Oddly, on Veterans' Day of 2012, he and Fiskerton disappeared from Mount Blackhead; it's unknown to this day why this happened.
- Zak is curious when he hears that Fuse is trying to mix legendary cryptids with his toxic fusion matter to create the ultimate fusion beasts; however, this attempt has not proven a real threat yet.
- It is unknown how Zak's Fusion counterpart was created.