One strip combines a bunch of fighter toys and dinosaur toys in Calvin's imagination to make the new menace of the Mesozoic era: "Tyrannosaurs in F-14s!!"
Calvin: This is so cool! Hobbes: This is so stupid.
Calvin also once demanded that his father read him a bedtime story in which the Three Bears eat the Three Little Pigs, and then team up with the Big Bad Wolf to eat Goldilocks and Little Red Riding Hood. Then, when Dad sarcastically asks what should happen to Hansel and Gretel, Calvin suggests that the witch should eat them - right before herself getting eaten by the Wolf.
And one of Calvin's most memorable fantasies had an engine on a jumbo jet explode, sending the smoking aircraft nosediving down toward the exact same spot where a derailed train is about to crash. That spot lies over a fault line that is just about to experience a record-breaking tectonic shift - and said fault line is right underneath the house of Farmer Brown...who is trying to light a match right next to a kitchen stove that has sprung a gas leak. As he strikes the match, Farmer Brown happens to glance out the window and manages only an involuntary Oh, Crap reaction before he is violently killed in four ways simultaneously.
In Peanuts Lucy once offered to do the cover art for Snoopy's "It Was a Dark and Stormy Night" novel. Snoopy suggested "How about some pirates and foreign legionnaires fighting some cowboys while some lions and tigers and bears jump over this girl who is tied to a submarine?"
When she did so, his reaction was "Needs more tigers".