The monstrous Turbo Toilet 2000 is determined to take revenge on George, Harold, and Captain Underpants.

When Princess Magnolia has to sneak out of her own birthday party over and over to change into her alter ego, the Princess in Black, to fight monsters, how will she keep her friends from guessing her secret? And, will she ever get to open her presents?

Portico Reeves' secret identity as Stuntboy allows him to use his superpower keep everybody safe, but when his superhero parents start fighting a lot he feels the responsibility to save them.

Buzz creates a comic book that features Buzz Boy and Fly Guy as the superheroes.

Afraid to go to horror movies with his friend, Pod, Squish the amoeba feels better after learning that even comic book superheroes get scared sometimes. Includes a science experiment.

Having changed the course of human history after unwittingly wondering what could be worse than going to prison, George and Harold are shot through time back to kindergarten, where they are subjected to bullying and a clueless school principal.

While on her way to brunch with another princess, Magnolia, and her unicorn Frimplepants, transform into the Princess in Black and Blacky to respond to a monster emergency.

"Harley Quinn loves fighting crime with her classmates like Wonder Woman, Batgirl, and Supergirl, but she always does it her with own madcap style--and a big mallet! It's no surprise that Harley can't resist getting involved with an upcoming inter-school battle of the bands and a fantastic cosmic carnival that appears only once a year--and this year, it's coming to Earth! But as things get stranger, Harley knows how to get to the bottom of a mystery--and...

Details the life of Wolverine, including his super powers and his battles alongside the X-Men.

When King Viking and his evil robot army attack Animal Town, and kidnap Singing Dog, it is up to Super Rabbit Boy, with some help from Sunny and his video game console, to save the day.