Starring Calvin Millan, son of "The Dog Whisperer" Cesar Millan, and his larger than lifeyellow dog named Stuff. The series follows the duo and their day-to-day activities at Mutt & Stuff, a wacky and whimsical school just for dogs.
Characters
Main
Calvin – The dog school's teenage teacher.
Stuff – Calvin's giant stuffed dog and best friend. In the double-length special "H.R. Pufnstuf Comes to Mutt & Stuff," it is revealed that his uncle is the title character of the Kroffts' earlier series H.R. Pufnstuf. He is very similar in appearance to Pufnstuf as well.
Zoe and Davenport – Two cats who comment on the action from a tree outside the dog school where they often exchange jokes, similar to the characters of Statler and Waldorf from The Muppet Show. They have a tendency to fall out of their tree while laughing at their own jokes while stating that they are OK. They also wear glasses.
Zippy – Calvin's pet dog.
Cesar – Calvin's father.
Melvin – A red, talking fire hydrant that is outside the dog school, and tells jokes.
Grandma – The dog in charge of the puppies while Calvin and Stuff are with the adult dogs.
Bow Wow – The automated A.I. of the Bow Wow Chow Snack Machine that appears in later episodes.
Marty and Sid – Two talking trees that were a gift from Stuff's uncle H.R. Pufnstuf that live on the playground. They are named after the show's creators, Sid & Marty Krofft.
Noodles – A mouse who lives in the wall next to the puppy tunnel; he loves to play jokes by pulling a rope and having confetti fall all over.
Junior Shades – A small dog who wears sunglasses. He appears in the episode "Dogs on a Plane" as co-captain with Zippy. He appears again in "Sherdog Bones" as a student at Mutt and Stuff.
Others
Clover – Cuddles' owner.
Owen – – Sunny's owner.
Luke – Dude's owner.
Dr. Christina – The dogs' veterinarian.
Popcorn Vendor that appears at the end of the episodes handing out popcorn to people and zippy jumping into him losing his popcorn
Annie the Animal Rescuer who guest stars and later becomes a recurring character in season two An animal rescuer who befriends Stuff and the dogs.
Guests
Marco – Calvin's cousin.
Gabby Groomer - the dog school's dog groomer and she appears in 2 season 1 episodes, "Skate Doggin" and Gabi's Groom-A-Thon and she also appears in 4 season 2 episodes, "The Wag 4 Rock Concert", "The Happy Hallowoof Party", "H.R. Pufnstuf's Happy Tree Jamboree", and "Surprise Birthday Balloon Bash".
Sergio Style Gabi Groomer's Brother appeared in the episode, "Surprise Birthday Balloon Bash".
H.R. Pufnstuf – Stuff's uncle who is from Living Island in the Krofft Series H.R. Pufnstuf.
Freddy the Flute – H.R. Pufnstuf's magic talking flute.
Cling and Clang – H.R. Pufnstuf's Rescue Racer Crew. Like in the original series, they never speak.
Olive – A skunk that appears in the episode "Bring In Da Noise, Bring In Da Skunk." All the dogs were scared of her and they wouldn't get along. After Noodles disguised Olive, the dogs got along with Shirley. While Calvin and the dogs were dancing, Olive's dress fell off. All the dogs were scared, and Calvin got confused. The dogs did a nose-to-nose with Calvin, then they were not scared of Olive anymore, and they found out that they could keep her.
Wally Whiskers – A comedian that appears in the episode, "Sit Stay, Stand Up".
Meow Meow Kitty – A villainous cat who takes over Mutt and Stuff, played by Jon Heder in season 2.
Simone Biles - appears as herself in season 2, helping the dogs compete and win a gymnastics competition.
Johnny in Charge - appears in multiple episodes, typically managing an event or attraction that the dogs visit.
Enchanted Irving - is a magician that visits Mutt & Stuff.
