Many times when Calvin got in trouble he brought up the alleged ‘noodle incident’. Any guesses as to what he did?
I have, BTW adapted this in my own vocabulary. Sometimes when my friend is pissed at me for something I ask him, “Is this about the noodle incident? Cause I’m really sorry about that!” 
I loved C & H, but missed the Noodle Incident reference on the first go-round.
Google tells me that the Noodle Incident was never elaborated. Intentionally. cite.
“Hamster Huey and the Gooey Kablooie (like “the Noodle Incident” I’ve referred to in several strips) is left to the reader’s imagination, where it’s sure to be more outrageous.”
–Bill Watterson, The Calvin and Hobbes Tenth Anniversary Book, p.200
I see that there the has been much speculation on this topic.
If I recall correctly, it was A: mentioned twice, B: supposedly a rip-roaring good story, and C: something so insane that Calvin didn’t take pride in having done it (now that’s a feat).
More than twice… Santa brought it up at least once that I know of.
Homer: [when asked why he was in a children’s library] They won’t let me in the big people’s library downtown. There was some…unpleasantness. I can never go back.
Encouraging wild speculation is part of the charm.
I believe the first mention was when his mom went to a parent teacher conference and got back before Calvin could pack and split. Calvin has managed never to be convicted for the incident.
Yup, you are correct, when he’s tabulating Calvin’s Christmas list with that geeky elf. “The tiger seems to vouch for him.”
Teehee.
The plot thickens!
There’s an earlier strip that goes something like this:
Calvin: Boy did I get in trouble at school today.
Hobbes: What happened?
Calvin: I don’t want to talk about it.
[Pause]
Hobbes: Did it have anything to do with all those sirens right about noon.
Calvin: I said I don’t want to talk about it.
I’ve always figured that was probably the noodle incident, though I have no proof.
That is my absolute favorite Calvin of all time. 
I’ve always imagined that the Noodle Incident stemmed from Calvin’s dad teaching him the tried-and-true method of testing pasta readiness by whether or not it sticks to the wall. Sure, Dad probably only showed him with one strand, but you know how excited Calvin gets …
I dunno, Draelin. If he was throwing an entire pot of noodles at someone, boiling water and all, maybe.
Well, I think it’s a much grander scale of noodle-sticking. Like the whole kitchen done in elbow macaroni, maybe with some fusilli theater-of-death sculptures complete with marinara sauce. Just throwing a few strands on spaghetti at the wall is tame for any child I know, and quadruply so for Calvin.
Calvin’s done a number of things that have made other people physically ill. Like squashing his sandwich and banana into his thermos so he can “choke it down all at once, and it saves my teeth unnecessary wear and tear!” Susie has a priceless look of revulsion in panel 3, and in panel 4, has taken her own lunch and booked out. Or the time he needed something for show-and-tell, then sneezed and said, “Never mind; do we have any baggies?” (Mom: “I don’t want to know…I don’t want to know…I don’t want to know…”
Now, compare and contrast with Jason Fox, who once tied all his spaghetti strands into one long rope so he could suck them all down at once. “Cool—I can pull it back out!” Jason and Calvin have a similar “do it to see if it can be done” mentality, though Jason tends more towards actively trying to gross other people out, while Calvin is simply bewildered that others don’t share his, uh, “tastes”.
But I think it’s most likely that Calvin did something with noodles that made the other students, and possibly some teachers, so traumatized that ambulances had to be called.
…while coming under suspicion for it, but managing not to be tied to it directly. Fascinating.
Well, on the one hand we have school, blaring sirens, noodle use and the not quite damning complicity of Calvin in the mix. Hmmm.
On the other hand, we have Calvin’s love for all things gross and dazzlingly unappetizing, such as the time he thought hamburgers were made from people from Hamburg and was put off only when he learned it was cow meat, and the time when he gluttonously ate his mother’s ficticious ‘monkey head stew’ with running commentary of each alien texture…
…I postulate a misguided teaching experience like an in-school ‘Shadow Employee Day’ with Calvin and the little seen lunch ladies and a cafeteria-served meal of rather volumous earthworms passed off as Calvin’s idea of ‘rigatoni’…
…the volumous earthworms provided by Calvin’s on the spot use of a casually discarded canned bulk spaghetti sauce cardboard box into a makeshift Duplicator Machine, of course!
I figure he dumped some spaghetti down Susie’s back and underestimated the consequences. I’m sure he did it with absolutely the best of intentions.
It would have had to backfire pretty badly on him if he didn’t want to mention it.
Really badly. He’ll gloat about stuff that he’s gotten beat up by Hobbes over, so the humiliation would have had to outweigh whatever he accomplished.
I figure he peed on the noodles, someone got a picture of it, and that’s where all the bumper stickers came from.
Yeah, what is up with all the Calvin peeing stickers? That’ll be tough for an anthropologist to explain 1000 years from now.