Zachary "Zach" Mitchell is a teenager who went on a trip to Jurassic World, with his younger brother, Gray. He is the older son of Karen and Scott, as well as the older nephew of Claire Dearing, the Park Operations Manager of Jurassic World.
The mother of Zach and his brother Gray allowed the two to take a trip to the dinosaur park Jurassic World, which their aunt Claire Dearing, was operations manager of. They were supervised by Claire's personal assistant Zara, as Claire was too busy to spend time with her nephews. They were spectators in the Mosasaurus Feeding Show and went on a Gyrosphere ride during their visit.
Isla Nublar Incident (2015)
However, the park's latest attraction, a genetic hybrid named Indominus rex, escaped during their trip. She attacked Zach and his brother while they were still in their Gyrosphere, but did not kill them. Some point after this attack he and his brother went into the restricted area of Isla Nublar where they found the ruins of the Visitor Center.
At one point amidst the chaos, Zach and Gray made it to Main Street only for a mixed flock of Dimorphodon and Pteranodon that were freed from their enclosure to attack the humans in the area. During this assault, they witnessed a Pteranodon pick up Zara and fly off with her, which led to Zara falling into the Mosasaurus' containment tank and both her and the Pteranodon being consumed by the aforementioned reptile. When the Indominus rex arrived Owen Grady protected them from the hybrid.