There's no character quite like Molly Shannon's Mary Katherine Gallagher, so in honor of the actress's birthday this week, we're taking a look back at some of her iconic character's hilarious — and hilariously awkward — moments in Superstar. Shannon first introduced the world to the clumsy Catholic schoolgirl on Saturday Night Live, and in 1999, Mary Katherine Gallagher made it to the big screen with the movie Superstar, which costarred Will Ferrell as cheesy high school hunk Sky Corrigan. The film featured Mary Katherine's most memorable antics, including the midconfession monologues, the tree-bark makeouts, and the sweet, sometimes heartbreakingly vulnerable moments that make the character so lovable. To celebrate Shannon's 50th birthday on Tuesday, take a look at 17 times Mary Katherine Gallagher gets wonderfully, hysterically weird.