This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)

Spectators dressed as leprechauns attend St Patrick's Day parade in Dublin on March 17, 2014. (Photo by Peter Muhly/AFP Photo)

“Aurora Hunters”. Photographers taking part in a photography tour on the Lofoten Islands in Norway, pull over on the side of the road to take a photo of their first ever Aurora Borealis after spotting it from their tour bus. Photo location: Rystad, Lofoten Islands, Norway. (Photo and caption by Mark Gee/National Geographic Photo Contest)

2016 Rio Olympics, Judo, Final, Women, 48 kg Bronze Medal Contests, Carioca Arena 2, Rio de Janeiro, Brazil on August 6, 2016. Otgontsetseg Galbadrakh (KAZ) of Kazakhstan and Dayaris Mestre Alvarez (CUB) of Cuba react. (Photo by Kai Pfaffenbach/Reuters)

South Korean football fans react during a public screening in Seoul of the South Korea vs Russia football match at the 2014 World Cup in Brazil, early on June 18, 2014. (Photo by Ed Jones/AFP Photo)

Italian actress Sophia Loren and US actor Marlon Brando at a cinema in Rome on November 11, 1954, where Brando received the Francesco Pasinetti Prize for his performance in the film “On The Waterfront”. (Photo by Keystone/Getty Images)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

The sun rises over the north sea as The Couple by artist Sean Henery sits just of the coast at Newbiggin-by-the-Sea, England, Wednesday October 8, 2014. (Photo by Owen Humphreys/AP Photo/PA Wire)