A man wearing a water-filled helmet in which a goldfish swims performs an act titled “Aquaman” during the Night Festival 2016 in Singapore, 20 August 2016. The ninth edition of the festival will run from 19 to 27 August and features installations and performances by a range of international and local artists. (Photo by Wallace Woon/EPA)

A Humboldt penguin stands on weighing scales whilst being photographed by members of the press during a photocall at the annual weigh-in at London Zoo in London, Britain, 24 August 2016. Every animal that is in the zoo is weighed and measured and the statistics recorded so the data can be shared with zoos across the world. (Photo by Hannah McKay/EPA)

A mass pillow fight in Trafalgar Square in central London on April 5, 2014 on International Pillow Fight Day. (Photo by Jane Scanlan)

Israeli mounted policemen move crowds of Palestinian protestors during a demonstration marking Land Day in the east of the city on March 30, 2012 outside the old city of Jerusalem, Israel. Land Day, which began in 1976, marks the day Israeli forces killed six Palestinians during a protest against Israeli occupation of what Palestinians consider to be their land. Palestinians around the world will commemorate Land Day with protests and demonstrations. (Photo by Lior MizrahiGetty Images)

People play Taiji on a square on August 08, 2011 in Luoyang, Henan Province of China. People all over China mark National Fitness Day on Monday in their own ways. (Photo by ChinaFotoPress/Getty Images)

A little girl takes a picture of a lion in the zoo in Frankfurt, Germany, Tuesday, September 13, 2016. (Photo by Michael Probst/AP Photo)

American reality show contestant Courtney Stodden is caught kissing a mystery woman on the beach in Santa Monica, CA on September 16, 2016. Courtney and the mystery brunette couldn't keep their hands of each other and didn't seem to care who saw their antics as they frolicked on the sand. (Photo by Canham/Splash News)

More than 400 people stripped off and ran into freezing waters to celebrate the autumn equinox – and raise money for charity at Druridge Bay, Britain, September 25, 2016. It was the largest turnout the North East Skinny Dip has ever seen in its five-year history, and it was also the first time it has ever rained on the morning of the event. Revellers gathered from 5.30am on Sunday at Druridge Bay, in Northumberland, before baring all in the North Sea. (Photo by David Charlton Photography)