
She finally appears when she rescues Buck and Crash and Eddie. Zee is seen making a couple of appearances before actually appearing in the story as she spies Orson, that came back from the Lava Falls thanks to his Raptors minions that he domesticated thanks to the fire as they're fascinated by it, to discover his plan to rule the Lost World. Due to this, they operated as adventurers on their own for years and they never saw each other again. Zee and Buck would exile Orson in the Lava Falls hoping that him being alone would make him feel some kind of remorse (it only made him more evil and sociopathic) and they split up after an argument. Orson refused and caused chaos in the Lost World, believing that mammals should not live in the Lost World and that the strongest should rule on the puny thus revealing his plan to rule the Lost World and prepared a trap for Buck that killed the whole team, except Zee and Buck.

However, a dwarf talking Triceratops named Orson wasn't happy about that as he hated mammals believing them to be inferior but Buck still offered him to become a member of his team due to feeling pity for his tragic childhood and for noticing his intelligence. Togheter, they decided to form a group of animals to defend the Dinosaur World from threats like Rudy or the Dakotaraptor family and allowed the Lost World to become a place for all the creatures in the world making more mammals live in the place.

There she met and developed a crush for Buck and became friends. Not much is known about her childhood but it's been told that at some point after Ice Age: Dawn of the Dinosaurs and before Ice Age: Continental Drift and Ice Age: Collision Course she finished in the Dinosaur World.
