I’ve always loved Skinner’s crazy explanations. Here are probably the two best, wherein they took the joke about as far as the could without stretching for humor, and they’re absolutely hilarious. 
From Whacking Day:
(Lisa answers a question about a battle)
RALPH: What’s a battle?
…
CHALMERS: Did that boy just say, “What’s a battle?”
SKINNER (quickly): No…he said…“What’s that rattle?”
CHALMERS (suspicious): Sounded like “battle”.
SKINNER: I’ve got a head cold, sir.
CHALMERS: I see. So you would hear 'B’s as 'R’s?
SKINNER: Yes.
From 22 Short Films About Springfield:
CHALMERS: Seymour!
SKINNER: Superintendent; I was just, uh, just stretching my calves on the windowsill. Isometric exercise. Care to join me?
CHALMERS: Why is there smoke coming out of your oven, Seymour?
SKINNER (quickly): Uhh, oh, that isn’t smoke, it’s steam. Steam from the steamed clams we’re having. [rubs stomach] Mmm…steamed clams.
…
SKINNER: Superintendent, I hope you’re ready for mouth-watering hamburgers!
CHALMERS: I thought we were having steamed clams.
SKINNER: Oh, no, I said, “steamed hams”. That’s what I call hamburgers.
CHALMERS: You call hamburgers “steamed hams”.
SKINNER: Yes, it’s a regional dialect.
CHALMERS: Uh huh. What region?
SKINNER: Uh, upstate New York.
CHALMERS: Really. Well, I’m from Utica and I never heard anyone use the phrase “steamed hams”.
SKINNER: Oh, not in Utica, no; it’s an Albany expression.
CHALMERS: I see.
Chalmers drops the questions for a moment and takes a bite.
CHALMERS: You know, these hamburgers are quite similar to the ones they have at Krusty Burger.
SKINNER (laughing): Oh, no, patented Skinner Burgers…old family recipe!
CHALMERS: …for steamed hams.
SKINNER: Yes.
CHALMERS: Yes, and you call them steamed hams despite the fact that they are obviously grilled. [shows Skinner the grill marks on his burger]
SKINNER (nervously): Uh… you know… one thing I sh–… 'scuse me for one second.
CHALMERS: Of course.
Skinner goes into the kitchen for a moment and returns yawning, as though he had been in there forever.
SKINNER: Well, that was wonderful. A good time was had by all. I’m pooped.
CHALMERS: Yes, I guess I should be – [notices kitchen is on fire] GOOD LORD, what is happening in there?!?
SKINNER (quickly): Aurora Borealis?
CHALMERS: Aurora Borealis?! At this time of year? A this time of day? In this part of the country? Localized entirely within your kitchen?!?
SKINNER (as if it were at all feasible): Yes.
CHALMERS: May I see?
SKINNER: Er…no.