Ricky Ricotta's Mighty Robot

Ricky Ricotta's Mighty Robot is a series of children's graphic novels written by Dav Pilkey (best known for his Captain Underpants books) and first seven books illustrated by Martin Ontiveros and all nine books illustrated by Dan Santat. In each book, Ricky Ricotta, a mouse, with the help of his mighty robot, saves the world from an evil villain. The books also have an alien animal from a different planet in order from closest-to-sun to farthest-from-sun including Earth, as the villain of the first book is from Earth. The reader could see the villains being jailed in each series and later notice the familiar villains from previous books. The first three books were initially published as Ricky Ricotta's Giant Robot. Dav Pilkey stopped using the word "giant" in 2002 after many young fans pointed out that the Robot is not a giant. He is just 12 times taller than a mouse, so he's only about 2.5 feet (76 cm) tall. Many young readers suggested the adjective "Mighty" instead, so after careful consideration, Pilkey changed the title of all the books.