Check Out Our Favorite Gorillas, Just in Time for the First-Ever World Gorilla Day

Koko, Kelly, Zola and Mshindi are wishing everyone a happy World Gorilla Day.

Experts are calling attention to the global plight of gorillas, a species that is rapidly facing extinction in the wild, with the first-ever World Gorilla Day on Sunday.

Read: See How Zookeepers Trick Animals Into Getting Weighed and Measured for Annual Checkup

The worldwide call to action, that invites zoos, sanctuaries and other organizations to join in on celebrations, was launched by the Dian Fossey Gorilla Fund International, and coincides with the 15th anniversary of the organization’s Karisoke Research Center, the longest-running institute of its kind.

Primatologist Dian Fossey dedicated her life to studying mountain gorillas in the Congo and Rwanda in the 1960s up until her death in 1985.

In honor of World Gorilla Day, is revisiting some of our favorite moments with the gentle giants.

Zola, a western lowland gorilla at the Dallas Zoo, went viral not once, but twice for his incredible dance moves when he was caught on camera spinning and splashing around a kiddie pool.

Kelly, a 30-year-old western lowland gorilla at the Los Angeles Zoo, exhibited a more serious demeanor during his viral moment-turned-meme when he appeared to be lecturing a crowd of zoo visitors.

While Koko, world famous for her extensive skills in sign language, did not become a mother, she did adopt several kittens, proving that she doesn't need to have a baby gorilla for her motherly instinct to kick in.

Read: Silverback Gorilla Unexpectedly Gives Birth, Zoologists Had Thought She Was Fat and Infertile

Although the world continues to mourn the death of Harambe, the gorilla shot and killed after grabbing a child and dragging him at the Cincinnati Zoo last year, Mshindi, a 29-year-old western lowland gorilla transferred from the Louisville zoo, is proving she fits right in with the other gorillas at the facility.

Watch: Children's Hospital Conducts Hearing Test on Gorilla After Keepers Suspected She Was Deaf