Competitors in costume cross a water obstacle during the Wildsau Dirt Run (Wild Boar Dirt Run) obstacle course fun race at Hellsklamm ravine in Obertriesting, Austria, October 22, 2016. (Photo by Heinz-Peter Bader/Reuters)

A gory fight to the death between snarling dogs and captured wild boars. Gathered around a bamboo-walled arena, Indonesians in this remote part of Java island seem eager to watch the blood-curdling contests, known locally as “adu bagong” (boar fighting). Not surprisingly, animal rights activists are up in arms against the regular spectacle, which began in the 1960s when wild pig numbers in this area in West Java soared and they were hunted to protect crops. Here: Women share a joke as they walk to a paddy field in Cikawao village of Majalaya, West Java province, Indonesia, October 12, 2017. (Photo by Reuters/Beawiharta)

People take part in the "Bison Race" winter extreme run competition in Zhodino, Belarus, December 5, 2015. (Photo by Vasily Fedosenko/Reuters)

Racing driver J. Gaal at the wheel of car number 26 at the RAC Tourist Trophy, run, for the first time, over the Four Inch Course on the Isle of Man, 17th September 1908. Gaal is racing in waterproofs. (Photo by Topical Press Agency/Hulton Archive/Getty Images)

A firefighter recovers after climbing the 1800 steps of the Costanera Centre Tower as part of the “Race for Life” aimed at encouraging organ donation in Chile, in Santiago, on October 16, 2016. More than 500 volunteer firefighters are expected to climb the 1800 steps of the tallest building in South America to promote and encourage organ donation in the country. (Photo by Claudio Reyes/AFP Photo)

Spunky runs during the third heat of a dog race Monday, September 1, 2014, at Canterbury Park, in Shakopee, Minn. Canterbury Park hosted their annual Labor Day Wiener Dog Wars in which dogs competed in seven races on the horse track for the title of Grand Champion. (Photo by Jeff Wheeler/AP Photo/The Star Tribune)

A man dressed as zombie takes part in a zombie race to raise funds for children with cancer at the child Hospital Manuel de Jesus Rivera in Managua October 19, 2014. (Photo by Oswaldo Rivas/Reuters)

A Nepalese army solder stand next to a horse during the “Ghodejatra” Horse Race festival, which is organised by the Nepal Army, in Kathmandu, Nepal, April 7, 2016. Ghode Jatra, the horse racing festival of Nepal, celebrated on the New Moon day of mid March or early April is among the important celebrations of the Kathmandu Valley. Grand horse parade including various acrobatic style of shows are performed by Nepal military at Tundikhel-a fenced parade ground located in the heart of Kathmandu city. (Photo by Navesh Chitrakar/Reuters)