Supernatural (TV series)/Recap/S02/E02 Everybody Loves a Clown

Season 2, Episode 2:

Everybody Loves A Clown
While hunting a supernatural creature that takes the form a clown, as well as pursuing their father's research on the Yellow-Eyed Demon, Sam and Dean discover the Roadhouse, a bar for, and frequented by, Hunters. Ellen Harvelle owns the Roadhouse, her daughter Jo works there, and a regular patron is Ash, a genius.

Tropes
"Dean: "Oh God please let that be a rifle."
 * Genius Bruiser -- Ash was kicked out of MIT for fighting
 * Or Are You Just Happy to See Me: When Jo presses a rifle against Dean's back:

Jo: "No, I'm just real happy to see you""

"Dean: "I know what you're thinking, Sam. Why did it have to be clowns?""
 * Why Did It Have to Be Snakes?: Dean references this when Sam announces that the Monster of the Week is a clown: