- The mysterious "Noodle Incident" is the Trope Namer. Infrequently, a character would reference a "noodle incident" that Calvin had been a part of, to which Calvin would immediately go into desperate denial or panicked defensiveness about. However, nothing about what happened during the aforementioned incident was ever brought up through the strip's entire ten-year run.
- The earliest reference to it was when Calvin's mom goes to a parent-teacher conference, and Calvin is dreading her return. When she gets home she catches him packing, which prompts him to immediately protest that everything was a lie, at one point bringing up "the noodles", which his mother had not heard of yet.Calvin: She told you about the noodles, right? It wasn't me! Nobody saw me! I was framed! I wouldn't do anything like that! I'm innocent, I tell you!
Mom: What noodles?
Calvin: Oh... Uh... Ha ha! Did I say noodles? You must have heard wrong. I didn't say noodles.
- According to a later Christmas strip, even Santa Claus doesn't know exactly what happened, or whether or not Calvin is innocent, despite having magical surveillance systems. He probably knows the broad outline, of course, since it's not that people don't know the details in-universe.
- Bill Watterson said in the Tenth Anniversary Calvin and Hobbes collection that he intended to visit the Noodle Incident someday, but the reason he never did was he decided that nothing he could come up with would ever be as funny as anything the readers would be able to come up with in their own minds.Calvin: I can't tell stories!
Hobbes: What about your explanation of the noodle incident?
Calvin: That wasn't a story! That was the unvarnished truth!
Hobbes: Oh, don't be so modest. You deserved a Pulitzer.
- The earliest reference to it was when Calvin's mom goes to a parent-teacher conference, and Calvin is dreading her return. When she gets home she catches him packing, which prompts him to immediately protest that everything was a lie, at one point bringing up "the noodles", which his mother had not heard of yet.
- One early strip mentioned the equally ambiguous "Salamander Incident". There, he claims temporary insanity.
- In one storyline that involved Rosalyn, Calvin's mom says she called seven other people and none of them agreed to babysit. She then tells Calvin, "You remember Amy? She just laughed when I called her." It's anyone's guess as to how Amy's night with Calvin went.
- At the end of the arc where Calvin and Hobbes accidentally push the family car into a ditch, Calvin comments about how surprising it was that his parents didn't yell at him for this. Hobbes starts to say, "But try keeping live worms in your dad's..." Calvin snaps, "Let's not talk about that, ok?!"
- There's a substitute teacher who appears in only one strip and is referenced in only three. She's introduced in the middle one, and in the last one, Calvin is walking with Hobbes and mentions that she left at noon.
- In this Sunday strip, Calvin tries to become a human kite by tying the kite string around his waist and having Hobbes fly him, but he's too heavy. They decide he needs to get lighter, and in the last panel, Mom is on the phone with the neighbor, who's complaining about a naked kid running around in her front yard, tied to a stuffed animal. Dad just says, "You handle it. I got the little nudist out of her bird bath, remember?"
Noodle Incident / Calvin and Hobbes