The China Mail - Hippo birthday: Thai internet sensation Moo Deng is a year old

Big crowds are expected at a four-day festival at Khao Kheow Open Zoo where Moo Deng -- meaning "Bouncy Pork" in Thai -- frolicked to stardom and amassed five million social media followers.

The first day of the extravaganza fell on a Thai public holiday with an agenda including a lecture on "Moo Deng's cheekiness", while a skincare beautician paid $3,000 to sponsor her fruit-festooned birthday cake.

Around 100 fans gathered outside her enclosure on Thursday morning -- fewer than the hordes she commanded at the height of her fame, but still animated with adoration.

Jennifer Tang took a week off her work in Malaysia to make the pilgrimage, telling AFP she was "a little bit obsessed" with the calf she described as a "chaos rage potato".

"She's really special to me, she makes me happy," she said. Tang insisted Moo Deng is "still really sassy and funny" despite approaching maturity.

"Take a look at the crowd today -- she's still a legend," she told AFP.

Moo Deng has swollen from five kilograms (11 pounds) at birth to 93 kilograms today.

She spent her birthday plodding in her enclosure, munching fruit and vegetables -- a stark contrast to the energetic yet clumsy antics that earned her fame as a pint-sized pachyderm.

"Moo Deng used to be very naughty and jumped around all the time," said Attaphol Nundee, one of her six handlers. "Now she only eats and sleeps."

"Her popularity has slowed," admitted the 32-year-old. "But some old fans have returned, and there are new ones too."

Despite her waning fame "her eyes light up when people take photos of her", he said.

Her handlers are set later to auction her belongings, but it is unclear what possessions she has accumulated in her short life at the Chonburi province zoo, a two-hour drive from Bangkok.

- 'Cute doesn't last long' -

Moo Deng's blubbery rose-blushed face launched a thousand memes and a plethora of merchandise including piggy banks, party shirts and popsicles -- prompting her owners to trademark her likeness.

She once quadrupled ticket sales for the zoo where she resides in a sparse, stone, five square metre (54 square feet) public enclosure, once livestreamed 24/7 to sate the internet's appetite for her.

There were hopes her stardom would spotlight the plight of the endangered pygmy hippo, native to West Africa with only around 2,500 left alive according to the International Union for Conservation of Nature

But social media and search engine metrics suggest Moo Deng's popularity peaked around late September last year before dramatically declining.

"Moo Deng went viral very quickly when she was born," said Joshua Paul Dale, an academic who teaches courses on the phenomenon of "cuteness" at Japan's Chuo University.

"Maybe part of our appreciation of cuteness is knowing that it's something that doesn't last very long," he told AFP.

Moo Deng is part of a pantheon of captive animals who have enjoyed flash-in-the-pan popularity for their cuteness online, including Australia's Pesto the penguin and China's Hua Hua the panda.

Pygmy hippos have a lifespan of between 30 and 50 years.

"Moo Deng won't be the most popular forever," admitted her handler Attaphol. "One day there will be a new generation of Moo Deng."

F.Jackson--ThChM