JOHN YANG: Finally tonight, a birthday celebration for a social media sensation.

JOHN YANG (voice-over): Thousands of adoring fans gathered at a zoo in Thailand this week for a four-day celebration of the first birthday of Moo Deng, the baby pygmy hippo that took social media by storm.

Her birthday cake, 44 pounds of fruits and vegetables, which she shared with her mother.

The zoo is about a two hour drive from Bangkok.

But fans came from much farther than that.

Molly Swindall flew about 8,600 miles from New York for her third time visiting Moo Deng.

On this trip, she had the honor of helping prepare her birthday breakfast.

MOLLY SWINDALL, Tourist: I just loved her so much and decided, you know what?

I have three days off, three or four days off of work.

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.

JOHN YANG (voice-over): Thea Chavez came from Houston.

THEA CHAVEZ, Tourist: Moo Deng has brought a lot of happiness to each and every one.

She's just a potato, a moist potato that has bursts of chaotic and calm energy at the same time.

JOHN YANG (voice-over): Jennifer Tang traveled from Malaysia.

JENNIFER TANG, Tourist: She makes me happy.

Whenever I'm like, stressed at work, I like pull up photos of Moo Deng so my whole office knows I'm here.

And here I'm like, okay, they let me take a week off.

JOHN YANG (voice-over): Moo Deng, Thai for bouncy pork, has been a social media star practically since birth.

Thanks to photos and videos, her keeper posts showing her many moods.

Sweet, playful, feisty, she's achieved mean status and has been featured in posts from X, a top German soccer team, the New York Mets, the Ultimate Fighting Championship, and even showed up on Saturday Night Live.

MAN: They're throwing shellfish and bananas at me, Colin.

No, Colin's head.

MAN: Hey.

You leave Moo Deng alone.

JOHN YANG (voice-over): Her birthday generated star sized crowds.

The zoo director said there were 12,000 visitors on Thursday afternoon alone.

While pygmy hippos tend to lose some of their playful energy around this age, they can live for as long as half a century.

So Moo Deng's fans likely have many more years to watch their favorite pygmy hippo grow into adulthood.