Koko's story is perhaps the most famous of unlikely animal stories, and we think it's adorable! Koko's teacher often read her books about cats, and when Koko was asked what she would like for her birthday she used sign language to say "a kitten". Not content with plush toys of kittens, Koko was soon given a kitten from a stray litter. She would nurse the kitten like a baby, until unfortunately one day the kitten escaped and was hit by a car. To cure Koko's sadness at her loss, zookeepers gave her two kittens who were in need of a home, and Koko showed her nurturing motherly love once more!