With black hair and a square face, a monkey at Hefei Wildlife Park in Anhui province has been viral on Chinese social media since early May.

The animal, a male black-capped capuchin, has been nicknamed Dazhuang — meaning "big and strong" — by internet users.

Despite spending 10 years at the zoo, the primate had received little attention until a visitor posted a video of him on Douyin, China's version of TikTok, during the May Day holiday, according to the park.

In Chinese, the character guo, meaning "country", is often used to describe a square-shaped human face, making the capuchin's distinctive look especially noteworthy online. Though Dazhuang is a primate, his facial features resemble those of a person, earning him the nickname "guo-character-face monkey".

"Dazhuang and another younger male of the same species were brought to our zoo from Hangzhou Safari Park in Zhejiang province in 2015," said Wang Huihui, a staff member at the Hefei park.

Last year, the zoo introduced a female capuchin from Wuxi Wildlife Park in Jiangsu province. She gave birth to a baby with Dazhuang in April.

The female monkey has been named Xiaomei, or "little beautiful", and is often referred to as Dazhuang's "wife". The younger male is now called Xiaoshuai, meaning "small handsome", and is considered Dazhuang's "brother".

Visitors frequently spot Dazhuang grooming Xiaomei while she cradles their baby. The trio has been dubbed "the happy life of Dazhuang" by fans.

Some online users have described Dazhuang as "ugly-cute", though Zhang Chunxue, the animal breeder who cares for the capuchins, disagrees. "Among black-capped capuchins, the alpha male usually has a squarer face and a bigger build than the rest," Zhang said. "By those standards, Dazhuang is actually very handsome."

Zhang added that the species has long, flexible tails capable of supporting their body weight, freeing up their hands for feeding or climbing. They are also among the few monkey species known to use tools, such as stones to crack nuts.

She described Dazhuang as gentle and slightly timid. "He climbs to a high perch and hides if approached by strangers," she said.

In recent years, animal "internet celebrities" have emerged across China, capturing public attention for their unique appearance, behavior or relatable expressions.

Last year, a chubby leopard at Panzhihua Wildlife Park in Sichuan province went viral, with people comparing it to the "leopard officer "from the animated movie Zootopia.

Earlier this year, white-faced saki monkeys Dudu and Huahua from Nanjing Hongshan Forest Zoo became internet sensations. Their baby, still unnamed, has also attracted public interest.

In 2023, a rotund fox at Yunnan Wildlife Park was nicknamed "Gas Tank", sparking social media buzz. And in 2020, two giant pandas at Hainan Wildlife Park became so plump that the zoo launched a "weight-loss" campaign for them.

Pan Yuyu, a Hefei resident, said the phenomenon reflects the deep affection Chinese people have for animals.

Zhou Liliang, general manager of Hefei Wildlife Park, said the zoo is working to maintain the natural environment of Dazhuang and his companions while minimizing the impact of increased visitor traffic.