How I Met Your Mother Season 1 Episode 10: "The Pineapple Incident"
Barney, Marshall and Lily convince Ted to do some shots. When he wakes up the next morning with no memory of what happened the previous night, he wakes up next to an unknown woman and a pineapple on his nightstand.
[on his theory, Carl, the bar tender is a vampire] Marshall: OK, think about this, is there even a single item on the menu that has garlic in it? Lily: Garlic fries. Marshall: OK, well, I'll get back to you