CHONBURI, Thailand (AP) – Thousands of excited fans flocked to a Thai zoo on Thursday to celebrate the first birthday of Moo Deng, the adorable baby pygmy hippo that has become a social media sensation.

The Khao Kheow Open Zoo was overrun with Moo Deng fans on the first of four days of activities marking the hippo's birthday. Children under 12-years-old can enter the zoo, about a two-hour drive from the capital Bangkok, for free throughout the extravaganza.

Many of Moo Deng’s fans flew miles to see her.

Among them was Molly Swindall, who traveled from New York for the celebrations. She was seen handing a tray of food to a zoo keeper for Moo Deng’s breakfast, which the baby hippo and her mother Jona quickly devoured.

“I just loved her so much and decided, you know what, I have three or four days off of work," said Swindall. "I can make it work to fly to Thailand. I will only be there for about 30 hours, but that’s enough to go see Moo Deng. And that’s exactly what I did.”

By Thursday afternoon, the number of visitors reached 12,000, zoo director Narongwit Chodchoy said. Despite the noise of visitors calling out for her attention, Moo Deng appeared peaceful as she took a dip in a pond in her enclosure.

Fans photographed the baby hippo with their cameras or cell phones and sang “Happy birthday” as her birthday cake, made of a variety of fruits and vegetables, was placed near the pond.

“Moo Deng is my happy pill, and she’s my energy pill, my curing pill. She’s my vitamin!” said Thea Chavez, who flew in from Houston, Texas.

Another fan, Jennifer Tang from Malaysia, leaned over the enclosure to take pictures.

“She makes me happy. Whenever I’m stressed at work I pull up photos of Moo Deng,” Tang said. "So my whole office knows that I’m here...They let me take a week off.”

The zoo held online auctions to celebrate Moo Deng's birthday, with photos, footprints, and a food container on offer to raise funds for all the animals under their care.

They also held an auction for the honor of sponsoring her birthday cake, which went for 100,000 baht ($3,065).

Moo Deng soared to stardom shortly after she was born, largely thanks to her keeper Atthapon Nundee who shared adorable pictures and videos of the baby hippo on social media. Atthapon keeps Moo Deng's fans updated on fun hippo moments – how she squirms as he tries to wash her, bites him as he tries to play, or calmly closes her eyes as he rubs her belly.

The name Moo Deng, which literally means “bouncy pork” in Thai, was chosen by fans via a poll on social media. It matches the names of her other siblings: Moo Toon (stewed pork) and Moo Waan (sweet pork). There is also another hippo at the zoo named Kha Moo (stewed pork leg).

The zoo – which sits on 800 hectares (almost 2,000 acres) of land and is home to more than 2,000 animals – saw spikes of visitors since shortly after Moo Deng was born. But Narongwit said the number of visitors has somewhat dropped since the height of Moo Deng’s fame. He said the zoo has had about 2,000 visitors during a weekday and around 5,000 during weekends over the past few months – about half the numbers it saw at its peak.

“Moo Deng is a representative of all wild animals, and she helps everyone understand the roles of zoos,” Narongwit told The Associated Press. “She speaks for all nearly extinct animals, and turns people's attention to their conservation.”

The zoo also runs breeder programs for many endangered species, including the pygmy hippopotamus. The species is native to West Africa, where it is threatened by poaching and loss of habitat. There are only 2,000 to 3,000 left in the wild.