Ace the Bat-Hound and Krypto the Super-Dog smell something fishy. Penguin's Bad News Birds have stolen sardines from the Gotham City Marina. Together, the doggy duo must reel in the fowl felons and throw them in the can.

Ray Palmer has found a way to shrink himself and his dog Spot to atomic size and become the superhero Atom--so when friend and rival Doris Zeul comes up with a way of increasing her size and becomes Giganta, it is up to Atom and Spot to convince her of the error of her ways.

Atlantis is under attack by the evil Ocean Master, and it is up to Aqualad, the Mermaid Nicoletta, and their superpets Fluffy the goldfish and Betty the beluga to defeat the supervillain.

The villain Scarecrow's servants, the Scaredy Crows, are coating Gotham City with fear dust, and it is up to Ace the Bat-Hound to find a way to save Halloween for the city's children.

Inside the giant robot he has built, Lex Luthor is rampaging through Metropolis smashing buildings, and it is up to Superhero Cyborg, and his two pet robots, F.E.L.I.X. and M.A.X., to stop Luthor and his mechanical monster.

When the Cat Crime Club use kryptonite to capture Krypto the Super-Dog along with other members of the Space Canine Patrol Agents and steal money meant for Metropolis' animal shelter, Krypto and his pals have to figure out a way to escape and capture the wicked cats.