Krypto, the Superdog, chronicles the comedic canine adventures of Metropolis' day-saving superdog from Planet Krypton. Krypto jettisons to Earth after traveling across the galaxies as a test-pilot puppy aboard a malfunctioning rocket ship built by Superman's father. Landing astray on unfamiliar terrain, the fully-grown Krypto swiftly seeks out companionship on Earth and flips over Kevin Whitney, a young boy who too longs for friendship. With an amazing array of super hero powers, ranging from heat vision to super strength to flying, Krypto partners with best pal Kevin to fight evil forces that threaten the safety and well-being of the people and animals of Metropolis.
Andrea exposes Krypto to a piece of red kryptonite by accident, which accidentally gives Kevin and Andrea powers when they touch him. It's up to Krypto and Streaky to make sure they stay safe.
Kevin plays one of his dad's old video games on Krypto's rocket computer. But when he gets transported into the game, Krypto and Streaky have to help him fight his way to the end.
When Mechanikat creates a robot double of himself, he soon finds that his creation has a mind of its own. He's left with only one option...ask the Dog Stars for help.
A guard dog for STAR Labs, named Buddy, slips into a vat of elastic chemicals and is able to stretch and mold his body. Can he help Superdog recover a stolen robot?
Mechanikat uses an aging ray on Superdog, but accidentally hits Kevin in the process as well. Can they restore their bodies back to normal?
Thundermutt asks Ace if he can study the way Ace fights crime so he can perform his new movie. Ace soon realizes the pain of helping him out.
Andrea follows Streaky into Krypto's clubhouse and finds out both superheroes' secrets. Meanwhile, Mechanikat creates a Dirtbot on Earth to steal jewels and uses kryptonite against Krypto and Streaky! It's up to Kevin and Andrea to destroy the Dirtbot.
Mertin the Magic Rabbit is wreaking havoc on the fair. However, things get worse when Krypto is caught in the act as well. Ace has to retrieve Krypto and try and out-magic Mertin with Stretch-O-Mutt!
When Ignatius gets bored, he clones himself with a new Lexcorp device. But when the machine gets out of control and creates endless clones of him, Superdog has to fetch them all.
The Supercat Fan Club wants to go on a field trip with Streaky. The Penguin's birds, however, have other plans for the heroes...
Isis steals a magical pipe that can control animals and uses it to rob stores in Metropolis. When Ace and Krypto end up under her spell, Jimmy the rat has to fight her off.
Mechanikat blocks out the yellow rays of the sun with his new satellite, creating red light instead. When Krypto and Streaky become powerless, Stretch-O-Mutt has to save the day!
Mammoth Mutt, Tail Terrier, and Paw Pooch compete for temporary leader when Brainy gets put to sleep by sleeping gas.
In order to find Krypto's secret rocket, Mechanikat sends Snooky in disguise to infiltrate the Supercat Fan Club. He soon comes to like his new friends, however...
Bailey returns to prove Krypto's secret identity as Superdog. Only this time, Andrea has to help Kevin keep the secret when he finds out about Supercat.
Peek and Pleek return to show Krypto and Kevin their latest criminal capture, named Plunk. But when Plunk escapes, a chase leads Krypto and Plunk into Streaky's body...
Stretch-O-Mutt is so excited to see the Dog Stars, however a pod enters with a space virus and infects the Dog Stars... except Krypto and Stretch-O-Mutt. To make things worse, the Dog Stars ship is struck by a Kryptonite ray. With all the Dog Stars sick, a weak Krypto and Stretch-O-Mutt must fool Mechanikat into thinking the Dog Stars aren't infected before Mechanikat and Snooky take over the ship!
Krypto is hit with a Cat-a-beam that makes him act and think like a cat! It turns out Mechanikat has conquered a planet and turned it into Catopia. Streaky finds the planet and thinks it's "heaven". Ironically, so does Krypto when he is forced to come with Mechanikat and be brainwashed. Streaky must find some way to change Krypto back, or Krypto will think he's a cat for the rest of his life.
When a parrot named Blackbeak and his rat pirate crew cause trouble in Metropolis, Streaky and Stretch-O-Mutt team up to put a stop to them. It seems like an easy task, but Blackbeak's pendant holds a special power.
"Robbie the Bird Wonder" returns from the South, only to get a jumpstart from Bat Hound because his superheroing hasn't been doing well. Both Robbie and Streaky notice that Krypto and Bat-Hound is missing, however, but manage to find where they are with Krypto wearing kryptonite over his neck and Bat-Hound tied to Krypto on a rocket. Streaky tries to save them, but gets caught as well. It turns out Isis and Mechanikat have teamed up, so now Robbie will have to save the day, despite having a bad time rounding up crooks.
While away at Summer Camp, Kevin overhears some beavers talking about conquering the humans. After following them, Kevin finds out that they are being led by alien beaver, named Buggy, who is helping them build weapons with the trees. After he is captured, he contact Krypto, who, along with Streaky, arrives to help. It's up to Krypto, Streaky, and Kevin expose Buggy's true identity to the beavers.
While Krypto's away, Streaky joins the Dog Stars on a missions to capture an intergalatic peanut pilferer. When the alien elephant gets away, they follow it to a giant peanut-shaped ship the size of a planet. Can Streaky and the Dog Stars successfully infiltrate the ship and get the peanuts back?
When Mechanikat is rejected as a leader of a club over Glorg, he sets to capture Superdog once again with a very powerful suit of his own. When Krypto and Ace get a distress signal (from their space suits), they land on a planet with Kryptonite dust and soil. With Krypto's weakened powers, will he and Bat Hound defeat Mechanikat's new makeover?
Brainy arrives outside Kevin's house, to tell Krypto that a new prankster/criminal is on the loose, so they try to guard a Timestopper, a device that freezes time. Meanwhile Barrump Barrump tries to steal the Timestopper from Kevin, but Kevin uses it to his advantage. Will Kevin's absurd usage of the Timestopper cost him the responsibility of guarding an important device?
After Kevin learns about the history of Hanukkah from Andrea, Krypto hears an alarm from the Lexcorp building just to find out Ignatious just wanted a toy named "Chippy Snowchip", and wants a ride to the toy store. Ignatious arrives at the stack of toys just to find out there is only one left. When a little girl finds Ignatious, everybody in the store screams. After Krypto repairs the store, he heads to the park to do snowmen. Andrea feels sorry for Ignatious, so she thinks about inviting him. Meanwhile, the snowchips Ignatious lost fall into each of the snowmen, causing the down lights to bring the snowmen to life!