Namely, even animals could not resist his charisma. For six months, a female gorilla, named Koko, has been grieving the death of her best friend and playmate. Therefore, back in 2001, the Gorilla Foundation in California asked Williams to try and brighten her up. Koko was an incredibly intelligent gorilla who comprehends the English language and could communicate by a modified version of the American Sign Language. She was born at the San Francisco zoo, lived most of her life in the Santa Cruz mountains, under the care of The Gorilla Foundation in Woodside. Her caregiver explained that she had a vocabulary of about 1,000 words of the Gorilla Sign Language. Koko also understood almost 2000 words in English, and it was reported that she had the intelligence of a three-year-old human child.

Things had not been going good for Koko since her friend died, and her caretakers thought of Williams, as the only man that could try and cheer her up. In the video, Williams refers to the experience as mind-altering, saying that he'd had an instant, genuine relationship with the gorilla. He was fascinated that she could understand him, respond, and express her feelings. He said: "We shared something extraordinary: Laughter. Koko understands spoken English and uses over 1,000 signs to share her feelings and thoughts about daily events, life, love, even death. It was awesome and unforgettable." In the video, Williams sits on a chair and waits for Koko to appear. At last, when she did show up, she sat on the floor, took his hand, and pulled him out of the chair to take a seat on the floor with her.

She held his hand to her nose for some time, absorbing his scent, like she was trying to sense his vibes. He remained calm, impressed by the human-like actions of the gorilla. When she felt secure, she revealed her playful side, and removed the glasses from Robin's face and tried them on. Then she got him tickling her, and even looked at his wallet, probably to check his ID and make sure he is the real deal. Clever girl. The duo laughed together, played, and crawled around her room. Koko appeared interested in his appearance and character, and Robin was eager to understand her thoughts. As Koko's caretaker Dr. Penny Patterson said, Williams managed to take her out of the darkness that she'd lived in for six months. She noticed that Robin made Koko smile, a thing that she hadn't done for 6 months, since the death of her childhood gorilla mate Michael, at the age of 27. In a tribute post to Williams, she added: "Robin's ability to just 'hang out' with Koko, a gorilla, and in minutes become one of her closest friends, was extraordinary and unforgettable. But not only did Robin cheer up Koko, the effect was mutual, and Robin seemed transformed." When this amazing encounter had to end, Koko had kissed his hand and gave him a big, warm hug.

Patterson stated that the gorilla was deeply hurt by Robin's death. When she overheard her caretaker talking about it, Koko even made the hand sign for the word "cry" with her hands. The photo below was taken after Koko found out about the sad event. Her guardians wrote that she became extremely sad, with her head faced down, and a trembling lip. Robin was living proof that laughter is the best medicine. The time spent with Koko was healing, and Koko smiled for the first time after a long time. The gorilla died in her sleep in 2018, at the prime age of 46 years. Robin managed to touch so many souls during his life, and even after his death, he keeps inspiring people all around the globe. As he said: "No matter what people tell you, words and ideas can change the world."