Thousands of fans have flocked to a Thailand zoo to celebrate the first birthday of Moo Deng, the baby pygmy hippo that's become a social media sensation.

It's a big happy birthday to Moo Deng who has celebrated turning one in style! The pygmy hippo became an internet hit last year after clips of her bouncing around went viral. Keepers at her zoo in Thailand are holding four days of festivities with plenty of birthday treats to celebrate her special day.

Thousands of fans have flocked to Thailand's Khao Kheow Open Zoo to celebrate the first birthday of Moo Deng, the baby pygmy hippo that has become a social media sensation.