Chinese netizens are mourning the death of Peng Peng, a giant panda that drew the adoration of people all over the world after a photo of it wearing a leaf hat was posted online. /CFP Photo

Peng Peng, born in 1999, passed away last Sunday at the China Conservation and Research Center for the Giant Panda in southwestern China’s Sichuan Province.  The cause was brain bleeding and epilepsy, which was brought on by encephalitis, the research center said. /CFP Photo

Peng Peng's age of death, 18, is the panda equivalent of 50 years old in humans. /CFP Photo

In the past six years, Peng Peng received special care for cataract-related eyesight problems. /CFP Photo

The center said Peng Peng’s body will be used in pathological study. /CFP Photo