A zookeeper feeds a hippopotamus with a watermelon in its enclosure in Belgrade's zoo, Serbia, July 20, 2015. Temperatures in Serbia have risen up to 40 degrees Celsius (104 degrees Fahrenheit), according to official meteorological data. (Photo by Marko Djurica/Reuters)

Protesters take part in “Artists Take Fight Against Police Murders” in New York's Times Square August 13, 2015. (Photo by Brendan McDermid/Reuters)

A worker holds harvested chillies at a chilli plantation in Pasir Datar Indah village near Sukabumi, Indonesia's West Java province, August 6, 2015. (Photo by Reuters/Beawiharta)

A cake decorated as a scene from the children's story “Little Red Riding Hood” is displayed at the Cake and Bake show in London, Britain October 3, 2015. (Photo by Neil Hall/Reuters)

A supporter of China's President Xi Jinping waits on the Mall for him to pass during his ceremonial welcome, in London, Britain, October 20, 2015. Xi is on a State visit to Britain. (Photo by Peter Nicholls/Reuters)

Canada's Yuri Nazarkin carves Star Wars character C-3PO (R) and R2-D2 for the ice sculpture festival in Liege, Belgium, November 13, 2015. (Photo by Eric Vidal/Reuters)

Elephants spray tourists with water in celebration of the Songkran water festival in Thailand's Ayutthaya province, about 80 km (50 miles) north of Bangkok, April 9, 2014. (Photo by Rungroj Yongrit/EFE)

Colored Pencil and Origami Landscapes: Ivanova's version of the popular Snake game features a chain-link origami snake chasing a butterfly. (Photo by Victoria Ivanova)