Brown panda
Brown pandaYoutube screengrab/Thita Manitkul

While the black-and-white giant panda is an Internet phenomenon for its endearing appearance, what has caught the fancy of Chinese social media users is a rare brown panda.

With only five brown pandas sighted in the past three decades, Qi Zai, as this panda is called, has understandably become a sensation.

Zai, who was found in China's Qinling Mountains as a cub, turned five this week, Chinese media reported. 

The brown-and-white panda looks distinct, and its appearance is because of a genetic occurrence, experts said.

'It is suspected that the brown and white colouring of pandas has a genetic basis, possible a result of a double recessive gene, a combination of genes or a dilution factor gene," American vet  Katherine Feng, was quoted saying by Daily Mail

All the five brown pandas sighted in the last three decades were from the Qinling Mountains, leading experts to believe that the climatic factors in the region could have a role in the rare looks of the animal, the report said. 

Qi Zai is being brought up at the Shaanxi Rare Wildlife Rescue, Breeding and Research Centre in China ever since it was found abandoned as a two-month-old pup. 

Since then, the brown panda has gone viral among Chinese social media users, CCTV reported.