Koko, the gorilla whose apparent aptitude for sign language endeared her to fans around the world, died in her sleep on Tuesday morning, according to the Gorilla Foundation, which oversaw her care.

"You key there me cookie." With that sign language, Koko the gorilla tells her mentor; 28-year old graduate student Penny Patterson, to get the key, open the closet and get a goodie out of the cookie ...

CALIFORNIA (WABC) -- A famous gorilla's maternal instincts immediately kicked in when she saw a litter of kittens. Koko, the silverback gorilla who can communicate with sign language, celebrated her ...

Koko the gorilla who mastered sign language, raised kittens and once playfully tried on the glasses of the late actor Robin Williams, has died. She was 46. The Gorilla Foundation says the western ...

Even though she couldn't speak, Hanabiko the gorilla could converse quite fluently, and was more fluent in sign language than the average human. Hanabiko — better known by her nickname Koko — died on ...