Gopher often says, "I'm not in the book." This has a double meaning: he's not in the phone book and he is also not in the A.A. Milne book. Gopher is the only Pooh character that did not originate in one of Milne's books. He was originally created to replace Piglet, until they decided to bring Piglet in for Winnie the Pooh and the Blustery Day (1968).
Posters from the initial release include pictures of Piglet and Tigger, who wouldn't appear until the next short, Winnie the Pooh and the Blustery Day (1968). The design for Tigger is closer to the original Ernest Shepard illustrations than the final design used on screen.