Dad and Cosima both think they're the best at pranking. Their prank war quickly spirals out of control, until Big Lizard finally reveals Proxima's real pranking champion!

Cosima takes over Dad's mission to film a unique underwater plant. But his special camera proves harder to operate than she'd thought, and Big Lizard keeps getting distracted.

Rex is missing, but Dad, Cosima and Big Lizard need him to save them from a giant slug!