"5"

From Peanuts Wiki

"5" made his first appearance in 1963. "5" appeared in A Charlie Brown Christmas, Charlie Brown's All-Stars, You're in Love Charlie Brown, He's Your Dog, Charlie Brown, It Was a Short Summer, Charlie Brown, You're Not Elected Charlie Brown, You're a Good Sport, Charlie Brown, It's Arbor Day, Charlie Brown, You're the Greatest, Charlie Brown, It's Flashbeagle, Charlie Brown and Why, Charlie Brown, Why?. He appeared in A Boy Named Charlie Brown and Snoopy, Come Home. He last appeared in 1981.