Captain Underpants and the Sensational Saga of Sir Stinks-A-Lot: Color Edition (Captain Underpants #12)

The Princess in Black

Dog Breath: The Horrible Trouble with Hally Tosis

Dragon's Halloween: An Acorn Book (Dragon #4)

The Princess in Black Takes a Vacation

The Bad Guys in The One?! (The Bad Guys #12)

Dragon Gets By: An Acorn Book (Dragon #3)

The Princess in Black and the Hungry Bunny Horde

Dragon's Merry Christmas: An Acorn Book (Dragon #5)

The Princess in Black and the Perfect Princess Party

Ricky Ricotta's Mighty Robot vs. the Mutant Mosquitoes from Mercury (Ricky Ricotta's Mighty Robot #2)

Sonic vs. New Yoke City

Ricky Ricotta's Mighty Robot (Ricky Ricotta's Mighty Robot #1)

The Bad Guys in Dawn of the Underlord (The Bad Guys #11)

Ricky Ricotta's Mighty Robot vs. the Naughty Nightcrawlers from Neptune (Ricky Ricotta's Mighty Robot #8)

Why?

Ricky Ricotta's Mighty Robot vs. the Unpleasant Penguins from Pluto (Ricky Ricotta's Mighty Robot #9)