Best practical joke I ever pulled off...
Many years ago, was on a road trip with ex-Mrs AF and ended up in Vermont dairy farm country.
She remarked how the dairy cows must get tired or worn out grazing on the steep hills that are all over in that part of the country.
I told her, with a long and elaborate back story of bullshit, how these cows were specially bred over the years to have two legs shorter than the other so that they could stand easy on the hills and graze in comfort. Told her I could not remember the proper name for them, that they were just called, colloquially, "Hill Cows".
Fast forward a few weeks and we're having dinner with family friends, who just happened to be ex-farmers from Pennsylvania.
Ex-Mrs AF starts telling them about our vacation and road trip, and sure enough, she starts expanding on "Hill Cows".
Her friend, Sue IIRC, was looking at her with a look of incredulity, while I'm starting to snicker and so is her husband.
"Honey, whoever told you that was jerking your chain, there is no such thing as a hill cow".
"No really, I
saw them and then Mr AF said...
OH YOU ROTTEN SON OF A BITCH!!!
"BWAHAHAHHAHAHHAHAHAH!!!!"