When Penelope Rex brings home Walter, the class goldfish, for the weekend, she is not sure how to feel, but when Walter goes missing, Penelope searches high and low for her fishy classmate.

How to care for a pet that eats 300 pounds of meat per day, has tiny arms, and a lot of slobber.

A young Tyrannosaurus rex with very poor eyesight loses his eyeglasses, resulting in chaos for himself and the creatures around him.

With school out Oona and her brother Bonk are busy helping their father gather food, but Oona's pet Stegosaurus is something of a cave wrecker when left at home all day, so the children start Camp Woggle where all the local pets can amuse themselves during the day--but Mauro's pet T-Rex is a problem because he has a tendency want to eat the other campers.