“Yippiee-Ki-Yay” has become a trademark of the franchise, but it was meant to be a joke

When they were filming the scene where Gruber was talking about cowboys, Willis just threw in the “Yippie-ki-yay, Motherf*cker” as a joke to crack up the crew, but instead, it worked so well that it was kept in the film. Now it’s been used (probably best in Die Hard 2), in every film of the franchise.

Though I’ll take the sanitized, Saturday afternoon movie version of “Yippie-Ki-Yay, Mister Falcon” any day.