It happened last January in a small European country Montenegro. 11-year-old female hippo Nikica escaped from the private zoo she used to live in for the past nine years. It was an accidental escape that happened during a flood. The hippo who lived in the backyard swam over the fence into the streets of the town. 9 days later Nikica came back home.
The two-tonne animal, considered one of the world's most dangerous, reportedly swam over the wall of her pen during heavy flooding in the Balkan country. The owners of the private zoo say they have to wait for flood waters to recede before trying to capture her.
Nikica has been wallowing in the water in Plavnica village, where she is a popular tourist attraction. Nikola Pejovic, one of the owners of the zoo, says her movements are being tracked by the zoo's private security and that she is "extremely tame and peaceful".
He told AFP news agency that she would probably stick to a path about 1km (0.6 miles) long, leading towards neighbouring houses in the village, near the capital Podgorica on Lake Skadar.
The hippopotamus, which is native to Africa, is one of the heaviest land animals. It is a plant eater that can weigh up to three tonnes.
Fiercely territorial, it can run faster than a human over short distances, and has powerful teeth and jaws.