A British Museum representative poses for photographs next to Andy Warhol's “Mao”, left, and Jim Dine's “Drag: Johnson and Mao” which feature in “The American Dream: pop to the present” exhibition during a media photocall at the British Museum in London, Monday, March 6, 2017. The exhibition, which opens to the public from March 9 and runs until June 18, charts modern and contemporary print making. (Photo by Matt Dunham/AP Photo)

“The Daleks are a fictional extraterrestrial race of genetically manipulated mutants from the British science fiction television series Doctor Who. Various storylines portray them as having had every emotion removed except hate, leaving them with a desire to purge the Universe of all non-Dalek life. Collectively they are the greatest enemies of the series' protagonist, the Time Lord known as the Doctor. Their famous catchphrase is “Exterminate!”, with each syllable individually synthesised in a frantic electronic voice” – Wikipedia

Photo: Max Hardy, aged 6, stands by a street sign from the Doctor Who Experience as Dalek, from the cult television show Doctor Who watches him on April 16, 2011 in London, England. The Doctor Who Experience Exhibition is currently running at Kensington Olympia Two, celebrating the science fiction programme that was originally screened in 1963. (Photo by Matthew Lloyd/Getty Images for BBC Worldwide)

Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

The competition, which is run by the Royal Observatory Greenwich in association with BBC Sky at Night Magazine, is now in its sixth year and has received over 2,500 entries. Photo: Centre of the Heart Nebula by Ivan Eder (Hungary). Situated 7500 light years away in the “W”-shaped constellation of Cassiopeia, the Heart Nebula is a vast region of glowing gas, energized by a cluster of young stars at its centre. The image depicts the central region, where dust clouds are being eroded and moulded into rugged shapes by the searing cosmic radiation. (Photo by Ivan Eder)

A cat wears a “Tsunagaru Col” gadget next to a smart phone displaying the connected app, at the Anicall Corp booth during the Wearable Device Technology Expo in Tokyo January 14, 2015. The gadget (“Tsunagaru” means connection) for animals tracks information about pets, such as the location and other animals the pet might be interacting with, with the purpose of providing “social networking” for animals. The expo runs until January 16 as a part of Japan's largest electronic exhibition expected to attract around 77,000 visitors, according to organisers. (Photo by Yuya Shino/Reuters)

In this October 14, 2013 photo, ecology professor Ricardo Freitas catches a broad-snouted caiman to examine, then release back into the water channel in the affluent Recreio dos Bandeirantes suburb of Rio de Janeiro, Brazil. Caimans are like tanks, a very old species with a remarkable capacity for renovation that allows them to survive under extreme conditions where others couldn't, said Freitas, who runs the Instituto Jacare, or the Caiman Institute, which aims to protect the reptiles. (Photo by Felipe Dana/AP Photo)

To most of us, hand-feeding crocodiles might sound like a one-way ticket to a watery grave. But for Jose Eduardo Chaves Salas, 32, coming within inches of the fearsome creatures’ razor-sharp teeth is all in a day’s work. He runs Jose's Crocodile River Tour on the Tarcoles River in Costa Rica, where tourists can watch him feed crocs up to 17 feet long. Photo: A tour guide shows a thumbs up as he sits on top of a crocodile on the Tarcoles river in Tarcoles, Costa Rica. (Photo and caption by Barcroft Media)