Krypto and Ace take on a mutant dog-plant hybrid who is stealing all the trees in Metropolis / An alien growth ray turns Melanie into a 50-foot giant toddler.

Krypto gets amnesia due to red kryptonite and can't remember who he is. The Junkyard Dogs try to turn him into a bad dog.

Furry Fish: Krypto and Streaky have an undersea adventure when red kryptonite turns them into fish.

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.

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.