When Stuff and the dogs put on a rock concert, they turn to Gabi Groomer to be their singer.
When Stuff breaks his favorite chew toy, a tiny Chew Toy Fairy arrives to fix it, but then her magic wand breaks.
When Stuff uses his new magic book to perform tricks, he accidentally turns Calvin into a chicken.
Zippy wants to enter an online contest to be the best action dog, but when his brothers show up, the siblings become competitive as they try to become the next Dog Star.
Olympic medalist Simone Biles comes to Mutt & Stuff and invites Calvin and the dogs to join her gymnastics team; Calvin teaches the dogs about being prepared.
When bossy Princess Pickles demands that everyone build her a princess doghouse, Calvin must teach her how to cooperate with her classmates.
Noodles the mouse plays too many jokes and causes lots of mischief, so Calvin reminds him not to take things too far.
The dogs must learn how to be good guests and follow the rules when Annie takes the class to a new doggy play space called "The Woof Zone."
When Super Sammy goes on vacation, the super villain Smarty Cat tries to turn Mutt & Stuff into a school for cats.
Siblings plan a party for their dog's birthday, but they argue too loudly over what kind of party to have and almost ruin the celebration.
A special day for twin dogs is held at the school, and the duos dress up in costumes and do tricks.
The dogs play video games all day, but Calvin wants them up and moving, so he contacts the famous gym instructor Jumping Jimmy.
A race is held at the school and TommyTortuga, the race tortoise, joins the fun and teaches Noodles a lesson about how slow and steady wins the race.
Sad about being the smallest dog at the school, Pixie tries to use a grow ray to make herself bigger.
Stuff tries to figure out which career he could do when a rescue dog, sled dog and seeing-eye dog visit the school.
When Zippy hits a home run to the bottom of the ocean, the dogs ride in a submarine to find the missing ball.
Calvin and the dogs go on a safari, but when the guide gets sad about not finding animals, the dogs help her search.
Calvin and the class must find a way to save their school when a determined train builder decides to build a train right through Mutt & Stuff.