The gorilla is famous for being able to express her emotions through sign language, even mourning the death of celebrity friend Robin Williams Kelli Bender is the Pets Editor at PEOPLE.

COLORADO SPRINGS, Colo. — The Cheyenne Mountain Zoo is mourning the death of one of their "gorilla icons." On Tuesday, the zoo humanely euthanized Roxie, a 48-year-old Western lowland gorilla.