Ricky Ricotta's mighty robot vs. the Naughty Nightcrawlers from Neptune - Dav Pilkey

From the creator of CAPTAIN UNDERPANTS, comes a BRAND NEW out-of-this-world
friendship adventure - in full colour!
Having a Mighty Robot as a best friend is great, especially when
he can help build a fort! But when Ricky's cousin Lucy shows up,
she renames the fort a "castle" and says it needs curtains - rats!
But these are the least of Ricky's worries. . . Nimrod Night Crawler
has created a wormhole so he can send his army of evil Night
Crawlers to help him take over the world, and Ricky's Robot is
trapped in a deep pit! Without his Mighty Robot, it's up to Ricky
- and an unlikely hero - to put a stop to this nightmare from Neptune!