A competitor scrambles in the mud under barbed wire during the Tough Guy Challenge 2009 at South Perton Farm on February 1, 2009 in Wolverhampton, England. The biannual event to raise cash for charity challenges thousands of international competitors to run through a gruelling set of 21 obstacles including water, fire and tunnels after a lengthy run at the start. (Photo by Christopher Furlong/Getty Images)

Ugly dog contestants Sweepee Rambo and owner Jason Wurtz celebrate in winning the 2016 World's Ugliest Dog Contest at the Sonoma-Marin Fair in Petaluma, California, USA, 24 June 2016. (Photo by Peter Dasilva/EPA)

People in traditional dance before competing in the 53rd Verdiales music contest in Malaga, southern Spain December 28, 2014. Verdiales is a form of traditional Flamenco music, which is common in the province of Malaga. Members of singing groups, known as “pandas”, wear traditional costumes decked with flowers and other accessories as they perform in the contest, which is held annually on December 28. (Photo by Jon Nazca/Reuters)

Phuket, Thailand. The girl is in the pool, which is higher than the land, and the elephant is on the land behind the pool. The photographer used an underwater bag to get a half submerged image. (Photo by Justin Mott)

“Catch of the Decade”. Can you guess what happened next? Photo location: Katmai National Park, Alaska, USA. (Photo and caption by Aaron Baggenstos/National Geographic Photo Contest)

“Sunward”. When the Mediterrenean Mantis opened its wings, It seemed very impressive at the sunshine... Photo location: Nicosia, Cyprus. (Photo and caption by Hasan Baglar/National Geographic Photo Contest)

“7584 Fish”. On a windy day right after a Cyclone passed the far northern Great Barrier Reef i took some friends out to the reef. Never before i saw that many glass fish on this particular coral “bommie”. Just when i setup my camera, this Napoleon Wrasse swam right through the school of fish building a living frame. Photo location: Cairns, Great Barrier Reef, Flynn Reef, Australia. (Photo and caption by Christian Miller/National Geographic Photo Contest)

“Diver in Magic Kingdom”. Green Lake (Grüner See) is located Tragöss Austria. In spring snowmelt raises the lake level about 10 meters. This phenomenon, which lasts only a few weeks covering the hiking trails, meadows, trees. The result is magical to watch diving landscapes. Photo location: Grüner See at Tragöss, Austria. (Photo and caption by Marc Henauer/National Geographic Photo Contest)