SAPPORO (Kyodo) Yaya, the oldest female Persian leopard in Japan, has died of breast cancer at age 18, the Sapporo Maruyama Zoo said in a release Monday.

In human years, the cat was over 80 years old, according to zoo officials.

Yaya was born in the zoo in May 1990 and soon became a visitors' favorite.

She began to grow weak last fall and before her Saturday death, slept most of the time.

Persian leopards are designated an endangered species and there are only about 10 in Japanese zoos.