The oldest giraffe living in North America died Thursday at the Cheyenne Mountain Zoo in Colorado.

Tamu, a female reticulated giraffe, died of natural causes at age 32, surrounded by keepers and vet staff, the zoo said in a statement. Although Tamu was considered geriatric, her health declined rapidly and unexpectedly beginning at 11 a.m. up until her death at 1 p.m.

“She was the nicest giraffe on the planet,” said Jason Bredahl, animal care manager. “She would sit under the lettuce hut and eat lettuce all day long and made millions of people’s days. If you have a giraffe selfie on your phone, there’s a good chance it’s with Tamu. She was a guest favorite, for sure.”

Guests and staff affectionately referred to the giraffe, who first arrived at the zoo in April 2003, as “Moose” or “Grandma” because of her “great heart” and “gentle” nature, the statement said.

Easily recognized by her dark, busy eyebrows, Tamu was due to celebrate her 33rd birthday on Dec. 28, FOX31 Denver reported.

In her lifetime, Tamu gave birth to six calves, leaving behind a legacy of 29 grandcalves, nine great-grandcalves, and one great-great-grandcalf.

"She will be missed so much," said Amy Schilz, senior giraffe keeper. "She was really, really smart. Just yesterday, she was participating in training for hoof care. She had a great heart."