The bus which Skipper catches to go to the headquarters has Goosebumps (1995) print ads on its side, along with the recommendation: "Two thumbs up".
When Skipper meets Libby on the bus, she tells him that she collects High School Harry and Bean Head comic books. a parody of Archie and Jughead.
This episode is based on Goosebumps book #25.
Attack of the Mutant has a similar premise with a book called "Startroopers: The Final Episode" by Kiwi author Ged Maybury which was published in 1991 by Scholastic which published the Goosebump books. The book is about Spencer Sockitt, a fan of a sci-fi franchise called "StarTroopers" who discovers that the StarTroopers are not imaginary and are real and Spencer and his friend Rebecca joins the StarTroopers as they fight their archenemy, a evil warlord called Kruel and his Blitzoid Army in a last battle for the universe.