Start humming the opening theme to Nickelodeon's classic "Doug," and any self-respecting '90s kid will surely join right in. Fred Newman, the man behind the doo-doo-doo's, didn't just give his improvised snap-and-pop to the show's theme and soundscape, though: he was also the voice of Skeeter, Porkchop, Mr. Dink, and the lead singer of the Beets.