At 46 years old, Koko the gorilla has died, The New York Times reports. She was born at the San Francisco Zoo in California on 4 July 1971 and was aptly named Hanabi-ko, Japanese for “fireworks child.” Koko was an anomaly, a rare instance of a gorilla who could communicate freely with humanity by using a modified version of American Sign Language. By the time she was 4 years old, she had developed a vocabulary of more than 170 words that grew to more than 2000 words at the time of her death. Koko’s famed linguistic ability landed her the cover of National Geographic in 1985 and 1987. Koko was a friend to many, including celebrities such as Robin Williams and Fred Rogers from Mister Rogers' Neighborhood, the show that featured her in an episode in 1998.