Hanabiko "Koko" is a female western lowland gorilla who has been taught American Sign Language beginning in 1972. According to Francine "Penny" Patterson, her long-term trainer, she is able to understand more than 1,000 signs of what she calls "Gorilla Sign Language" (GSL) which is based on ASL, and understand approximately 2,000 words of spoken English. Koko also gained publicity when she reportedly adopted a kitten.

This is old footage of Koko the gorilla loving and caring for a pet kitten and then crying whenever she finds out the kitty died. If anyone says animals don't feel emotions, show them this.