Koko (gorilla)
Hanabiko, nicknamed "Koko" (July 4, 1971 – June 19, 2018), was a female western lowland gorilla born in the San Francisco Zoo and cross-fostered by Francine Patterson for use in ape language experiments. Koko gained public attention as the subject of two National Geographic cover stories and, in 1985, the best-selling children's picture book, Koko's Kitten.