Who is this selfie superstar?

If you're having a bad day, these pictures are for you.

Look at that smile! This isn't a stuffed toy. VCG Photo

This quokka, a small macropod from Australia. /VCG Photo

It is a "selfie superstar" as thousands of tourists visit its homeland to take selfies with it. /VCG Photo

Its super cute "smile" melts hearts and earns it the reputation of being "happiest animal on earth." /VCG Photo

Are you talking to me? /VCG Photo

This little mammal's sweet "smile" will definitely make your day. If you live in, or have been to Western Australia, you must know the quokka, a local and international superstar.

A woman takes a selfie with a mischievous-looking quokka. /VCG Photo

A couple takes selfie with a jovial quokka. /VCG Photo

A group of tourists pose happily for a selfie with an excited quokka. /VCG Photo

Tourists post selfies with quokkas on social media. /VCG Photo

A woman takes a selfie with a quokka on the ground by a tree. /VCG Photo

The quokka is a close kin to kangaroos and wallabies. In Chinese, its name can be translated to "short-tailed short kangaroo." But its tail is not very short. The cat-sized marsupial has a tail measuring 25-30 centimeters, which helps it keep balance both on land and trees. It looks like a big rat. The quokka is excellent at climbing trees.

"I am NOT a big rat!" /VCG Photo

The quokka is a nocturnal herbivore. The gentle animal does not harm and is not afraid of humans. Therefore, thousands of tourists are attracted to its habitats to take selfie with these cuties every year. Even many celebrities, including Hollywood movie stars and British royal family members, have posted selfies with quokkas on social media. The quokkas have the reputation of being "happiest animal on the planet."

Swiss tennis star Roger Federer takes a selfie with a Quokka at Rottnest Island, Australia. /VCG Photo

However, these surreal angels are facing real threat. The species is listed as "vulnerable" in the IUCN red list, with a low population of 7,500 to 15,000. The threats include droughts and wildfires, which are frequent in Australia. They are also easy to fall prey to cats, dogs and foxes. As Australia lacked predators before humans arrived, the quokkas have not evolved to have many self-defense skills.

The Duke and Duchess of Cambridge feed a quokka during a visit to Taronga Zoo, Sydney. /VCG Photo

Too much love from humans may be dangerous for them as well. As herbivore, the quokka cannot digest human food and gets sick easily. Being fed by tourists can also cause dehydration and undernourishment. If you have the opportunity to visit these angels, please remember never feed quokkas human food.

(Cover photo via VCG, designed by CGTN's Jia Jieqiong)

(If you want to contribute and have specific expertise, please contact us at nature@cgtn.com.)