Speaking with a whistle, the helpful gopher from Disney's Winnie the Pooh proudly announces that he's not in the book. In context, he means that he's not in the phone book, but he's also not in the AA Milne books either.
Who should be blamed for this pun? Walt Disney himself, who inserted the joke after several animators questioned the gopher's inclusion. In the film, the gopher is enlisted to help extricate the tubby Pooh from Rabbit's front door. He would later join the characters on their various other adventures in the different Winnie the Pooh films and television shows.