Competitors carry crosses at the start of the annual Tough Guy event in Perton, England on January 29, 2012. Though the endurance race is one of the most difficult of its kind, with competitors often failing to finish and injuring themselves, racers still display a sense of humor in their dress and appearance on race day. Billy Wilson, who goes by "Mr. Mouse," stands at the Tough Guy starting line in Perton, England on Jan. 29, 2012. The formal Royal Army Grenadier Guardsman first organized the race in 1986, and the grueling competition is held as a fundraiser for charities each year. A competitor wears bunny ears as she begins the Tough Guy race on Jan. 29, 2012. Competitors as young as 16 years of age are allowed to compete in the race, as long as they are insured. On average, a third of the competitors do not finish - and even the winners sometimes suffer from hypothermia and other injuries. A competitor crawls underneath barbed wire during the Tough Guy competition on Jan. 29, 2012. A competitor gets dangerously close to the flames as he hurdles an obstacle during the Tough Guy challenge on Jan. 29, 2012. A runner wearing face paint and a top hat emerges from water during the Tough Guy competition on Jan. 29, 2012. Racers wade through water during the Tough Guy challenge on Jan. 29, 2012. The eight-mile course includes a long stretch of wading through muddy water, in what are already frigid January temperatures. A man emerges from a water obstacle on during the Tough Guy challenge on Jan. 29, 2012. The obstacles have intentionally fearsome names, often referencing wars, to match their difficulty; one particularly difficult series of fire and barbed-wire obstacles is named the "Killing Fields." Competitors in dress clothes walk across a muddy path during the Tough Guy challenge on Jan. 29, 2012. Competitors scale a cargo net during the Tough Guy competition on Jan. 29, 2012. Competitors jump off of logs at the "Death Plunge" obstacle on Jan. 29, 2012. Competitors hurdle over hills of mud after passing a fire obstacle during the Tough Guy competition on Jan. 29, 2012.