Koko was probably the most famous real-life primate of all time. That’s because she was remarkable. Koko was a gorilla who learned to communicate with human beings through the use of sign language. Last week, Koko died at the age of 46—here’s a look back at her remarkable life.

Birth

Koko was specifically a western lowland gorilla. Born at the San Francisco Zoo in 1971, she spent her life at The Gorilla Foundation, located in the Santa Cruz Mountains in central California.

Name

“Koko” was merely a nickname. Her full name is Hanabiko, which in Japanese means “fireworks child.” That’s because Koko was born on the fourth of July, a big fireworks holiday.

Fame

Her claim to fame was, of course, her amazing abilities to converse with humans, and give us all a glimpse into how a gorilla’s mind works. She could listen to conversations, follow them, and used sign languages to talk. At the time of her death, she had an American Sign Language vocabulary of more than 2,000 words.

Pets

In addition to her communication abilities, Koko also gained fame and affection for being one of the most devoted cat-lovers in the world. The young gorilla so loved to look at cat-based picture books and story books that in 1984, she asked her team of researchers for a kitten. They provided a stuffed toy kitten, but Koko didn’t like it — she signed “sad” in regards to the toy. And so, on her next birthday, she got to pick out her own real kitten from a litter. The first one, which she named All Ball, became world famous as the star of the bestselling 1985 children’s book Koko’s Kitten. Sadly, All Ball escaped from Koko’s enclosure and was hit by a car (Koko reportedly cried for days and signed, “Sleep cat.”) Koko went on to have more cats, though—just three years ago, she adopted two kittens named Ms. Gray and Ms. Black.

“Family”

The Gorilla Foundation brought in an orphaned gorilla named Michael as a potential mate for Koko. They became best friends instead. When asked why she didn’t want to breed with Michael, Koko said he felt “like a brother.”

Grief

In the sixth months after Michael died, Koko was despondent – researchers said she didn’t smile at all, didn’t sign much, and ate less. In other words, she was mourning. In 2001, researchers brought in a guest—comedian and actor Robin Williams. The frenetic, energetic comedian helped Koko snap out of her depression as they laughed, and played games. They remained friends, so much so that when Williams died in 2014, Koko sensed something was wrong among her handlers and asked what had happened. They told her Williams died, and she went into mourning.