Participants compete in the Mud Day Race extreme run competition at El Goloso military base, outside Madrid, Spain, June 11, 2016. Thousands of athletes got covered in mud as they celebrated International Mud Day running a 13-kilometer obstacle course on a sunny Saturday with heatwave-like temperatures up to a 29 degrees Celcius (around 84 degrees Fahrenheit). (Photo by Juan Medina/Reuters)

Competitors release their hens during the World Championship Hen Racing Championships in Bonsall, Britain August 1, 2015. (Photo by Darren Staples/Reuters)

A participant peeks from his costume before the start of the the annual London Pantomime Horse Race in Greenwich, Britain December 13, 2015. (Photo by Neil Hall/Reuters)

A participant competes in the “Nostalgic Ski Race” in the western town of Neuastenberg February 8, 2015. The “Nostalgic Ski Race” is held every two years with about 40 participants and is organized by the ski club of Neuastenberg, a town which was founded in 1713. The conditions for the participation in the race are vintage skis and dresses. (Photo by Ina Fassbender/Reuters)

Pigs race around the track at the Pig Racing and Diving display at the Sydney Royal Easter Show on April 10, 2009 in Sydney, Australia. (Photo by Mark Kolbe/Getty Images)

People attend the Stranavigli Water Race held at the Naviglio Grande on July 16, 2011 in Milan, Italy. Stranavigli Water Race is an annual creative contest on the water. (Photo by Vittorio Zunino Celotto/Getty Images)

Hollowed pumpkins float on a lake Ludwigsburg Castle on September 19, 2010 in Ludwigsburg, Germany. (Photo by Ralph Orlowski/Getty Images)

Participants sit on a cable chair as they take part in the 30th edition of the Belalp Witches Ski Race on January 14, 2012 in Belalp, Switzerland. The race is inspired by a legend dating back to the middle ages, of a witch who tormented villagers in the area until she was burnt to death. (Photo by Harold Cunningham/Getty Images)