It MUST be the punchline of a joke you know. Not something that could be the punchline of a joke. Examples and the first two.
And the bartender asked him “Do you think I asked the genie for a 12 inch pianist?”
And the Mother Superior answered “25 dollars, same as in town.”
“Maybe I should have said Joe Dimaggio?”
“There goes the bell. Now we have to go in and string beads.”
“Who’s confessing? I’m bragging.”
“You don’t eat a pig like that all at once!”
He had snap and crackle, but no pop.
“Hey! It’s a talking muffin!!”
“Okay, coffee break is over. Everyone back on your heads.”
“Move over, girls. I have to gargle.”
“Hell, no. I’m trying to get the taste out of my mouth.”
“Excuse me, you gonna eat that?”
“They took her picture off the box because her box is in pictures.”
“Neither have I. Must be the cobbles.”
“Yes it does, doesn’t it?”
The old guy looks around, and makes sure that nobody is listening, and leans to the man, and he says: “but if you fuck one sheep…”
“Don’t worry, we’ve got another one in the boot.”
“You don’t usually come in before four o’clock, Father.”
“Hey! I can see your house from up here!”
“Gee whiz, Mom! You’re always spoilin’ my tricks!”
“I didn’t have holes in my feet the last time!”
“Anybody wanna buy a fly?”
“I don’t know… maybe you should just pet him first.”
“Move the cat and I will.”
“Dick van Dyke.”
“What is this, some kind of joke?”
“The aristocrats!”
“You can keep the duck.”
“Admit it, you’re not here to hunt are you?”
“You’re so freakin’ smart, you tell me!”
“I was talking to the duck!”
“BITCH!”
“I learned to say ‘How very nice!’ instead of ‘Fuck you, bitch!’”
“Hey, Masked Man! You left yer Injun runnin’ ouside!”
“Ugh, what you mean ‘we,’ White Man?”
“Ugh, me sorry Chief. That not bacon tree, that 'am bush.”
“Well, ma’am, looks like this just ain’t your lucky day!”
“So the bear grabs the rabbit and wipes his ass with it.”
“Yeah, and it’s deep, too.”
“That’s okay. My name is Kevin, and I’m on my way to a costume party.”