Jimmy and Mark Ruffalo take turns drawing questions from the best friends box and guessing each other's answers.

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The Tonight Show Starring Jimmy Fallon features hilarious highlights from the show including: comedy sketches, music parodies, celebrity interviews, ridiculous games, and, of course, Jimmy's Thank You Notes and hashtags! You'll also find behind the scenes videos and other great web exclusives.

The Best Friends Challenge with Mark Ruffalo
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