[1] In each book, Ricky Ricotta, a mouse, with the help of his mighty robot, saves the world from an evil villain.

Many young readers suggested the adjective "Mighty" instead, so after careful consideration, Pilkey changed the title of all the books.

Fortunately for Pilkey, Santat agreed to re-illustrate all seven books, plus illustrate two new remaining, unpublished Ricky Ricotta's Mighty Robot adventures.

In a secret cave on a mountaintop, the crazed rat scientist, Dr. Stinky McNasty, creates a giant robot to destroy Earth.

The story starts when Ricky Ricotta and his Mighty Robot are late for supper because they were in the Hawaii collecting seashells.

Meanwhile, on Venus, the Voodoo/Video Vultures are frustrated with the unbearably hot atmosphere of their planet, which reduces their food into a melted mess.

Ricky and his Mighty Robot realize the following day that the mice are hypnotized and have been ordered to bring food to the army of Voodoo/Video Vultures.

With the robot captured, Major Monkey and his army of Mecha-Monkeys launch an all-out assault on Squeakyville.

Ricky's parents race home the heroes in their new rocket-powered minivan, and everyone has cheese pizza and root beer for dinner.

It is Ricky Ricotta's birthday, and his parents plan to take him to the dinosaur museum with his annoying cousin, Lucy ("Oh, NO!

While the Robo-Rabbits bake food for her, Ricky sneaks upstairs and finds General Jackrabbit with the Meany Machiney.

Ricky then switches the complex controls from "Big, Ugly 'N' Evil" to "Little, Cute 'N' Sweet" and then zaps the Jurassic Jackrabbits.

Then, the three rabbits are put into their rocket ship and thrown back to their home planet by the Mighty Robot.

(Lucy will be the beautiful princess, Ricky will be the ugly prince, Cupcake, Fudgie, and Waffles will be the royal ponies, and the Mighty Robot will be the brave knight) Meanwhile, on the dark, smelly, polluted world of Saturn,[a] Sergeant Stinkbug grows tired of the planet and decides to find another world to dump junk.

When he sees Lucy, Sergeant Stinkbug swoops down to Earth and kidnaps her while Ricky and his robot and the three Jurassic Jackrabbits are snacking away.

However, Uncle Unicorn starts the backup generator and makes the Ladybot grow into a bigger, deadlier machine ... who trips over almost immediately after activating.

Ricky Ricotta's Mighty Robot vs. the Naughty Nightcrawlers from Neptune (2016) is a children's novel by Dav Pilkey and illustrated by Dan Santat.

Nimrod launches a rocket with an inflatable teleporter (wormhole) to planet Earth, which crash-lands on Farmer Feta's property.

Through the wormhole, Nimrod convinces the Farmer that he can stop Ricky and his robot for their annoyances by digging tunnels under his property.

The army of Naughty Nightcrawlers dig straight under Ricky's fort, causing the ground to become unstable.

Finding themselves in Neptune's caverns, Ricky and Lucy happen upon nightcrawler guards watching the destruction of Squeakyville.

At that moment, the Mighty Robot comes to the rescue, having been dug up by the drilling suit Lucy rode on the way back.

The story concludes with Ricky, the Robot (using the deactivated wormhole as his inflatable tube), Lucy, and her pets swimming around in the backyard pond.

Ricky Ricotta's Mighty Robot vs. the Unpleasant Penguins from Pluto (2016) is a children's novel by Dav Pilkey and illustrated by Dan Santat.

Back on Earth, Ricky decides to show Lucy how sorry he really is (he has to explain the meaning of "making amends" since the robot is unfamiliar).

The robot flies Ricky to Hawaii to gather beautiful wildflowers, and when the two return, they spend all night planting them on a mountain in Squeakyville for Lucy to see.

President Penguin lands on the word "HOORAY"), Lucy and her Jurassic Jackrabbits race to the spaceship, unaware that the ship is not actually part of the surprise.

Lucy and her pets hear the commotion, and when they see what has happened, Clancy and Nigel explain the reason behind the President's actions.

The explosion sends everyone flying, and after the Mighty Robot saves Ricky in the nick of time, President Penguin is put into the cooler.

It contains puzzles, true-or-false, and even a first peek at the Naughty Nightcrawlers from Neptune and the Un-Pleasant Penguins from Pluto (though these two installments were not released with illustrations by Ontiveros).