Zac Efron has come a long way since he starred in musicals in high school and High School Musical—he is now starring opposite Martin Scorsese's muse, Robert De Niro, in the prestige film Dirty Grandpa. But last night, Jimmy Kimmel unearthed a video he got from Efron's old teacher in which he moonwalks as Snoopy in a production of "You're A Good Man, Charlie Brown." Watch Efron sing, back when he was just a little Peanut: