While his human Elliot adjusts to his new home and stepfamily, Gizmo, an evil genius guinea pig, searches for a new evil lair where he can plot to take over the world, but Gizmo is constantly thwarted by Elliot's little stepsister Jasmine (who likes to play dress-up), Abuela (who may or may not like to eat cavies), and Wedgie (a Corgi superhero and Gizmo's nemesis).

Mama, Sister, and Brother are excited about the puppy they bring home from Farmer Ben's farm, even though she takes a lot of care.

When Buzz captures a fly to enter in The Amazing Pet Show, his parents and the judges tell him that a fly cannot be a pet, but Fly Guy proves them wrong.

Arthur's new puppy causes problems when it tears the living room apart, wets on everything, and refuses to wear a leash.

Except for his bath, Fergus experiences the perfect doggy day, from chasing cats and motorcycles to being scratched on his favorite tickle spot.

When a white dog with black spots runs away from home, he gets so dirty his family doesn't recognize him as a black dog with white spots.

Although Henry's cousin Annie likes his dog Mudge, when she gets her own pet she decides that a bunny will be perfect for her.

When Lucy, a young bear, discovers a boy lost in the woods, she asks her mother if she can have him as a pet, only to find him impossible to train.

Fearing for the safety of the third grade's class pet, Cheese the rat, Rosemary takes him home in her backpack and creates chaos in the household.