A. A. Milne added Owl and Rabbit because he needed more
characters for plot development. There was never a Rabbit or Owl
animal owned by Christopher Robin. When Walt Disney studies started
making vooks, movies and videos of the Winnie The Pooh stories they also
felt this need for another character.
They added an engineering genius, Gopher, who constructed things needed
by the characters in the Hundred Acre Woods. Since he was added by
the Disney Studios, there are neither stories about Gopher by A. A. Milne,
nor illustrations by E. H. Shepard..