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The title of "world's most famous animal" would be a hotly contested one, but Koko — a Western Lowland gorilla living in Woodside, California — is certainly in the running.
Koko's been on the cover of National Geographic on more than one occasion. She's hung out with Leonardo DiCaprio and William Shatner.
The reason for her fame? She can communicate with humans.
She's been the subject of many news articles over the years, but a BBC crew has been given "unprecedented" access to film her for a month for their new programme — Koko: The Gorilla Who Talks to People.