Moo Deng, a viral pygmy hippo, has become an internet sensation, but zoo officials are worried about her safety.

Only a month after the adorable baby hippo Moo Deng was unveiled on Facebook, her fame became unstoppable both domestically and internationally.

Two-month-old baby hippo Moo Deng and her mother Jona are seen at the Khao Kheow Open Zoo in Chonburi province, Thailand (Sakchai Lalit/AP) Mr Atthapon, who has worked at the zoo for eight years taking care of hippos, sloths, capybaras and binturongs, said baby hippos are usually more playful and energetic, and they become calmer as they get older.