“A Balinese man shows off his pride and joy, a fighting cock, while on a cigarette break after a morning’s work in nearby fields”. (Photo by Coltrane Koh/The Guardian)

Bulls fight during the Maghesangranti festival at Talukachandani village in Nuwakot district near Kathmandu, Nepal January 15, 2016. The village organizes the bullfight during the Maghesangranti festival that commemorates the start of the holy month of Magh, ushering in the coming of warmer weather and longer days. (Photo by Navesh Chitrakar/Reuters)

Indigenous women from the Kamayura tribe take part in a demonstration of Huka Huka fight at the first World Games for Indigenous Peoples in Palmas, Brazil, October 29, 2015. (Photo by Ueslei Marcelino/Reuters)

These greenfinches go head to head in what appears to be a heroic fight or a playfull moment together, inspiration for a new version of “Angry Birds”, in Trezzo Sull'Adda, Italy in March 2013. (Photo by Marco Redaelli/IMP/AbacaPress.com)

Miesha Tate, UFC women's bantaweight shows the media how to fight during a UFC press conference at Akasaka Garden City on August 26, 2014 in Tokyo, Japan. (Photo by Atsushi Tomura/Getty Images)

Charlotte fights a monster with a “wand” in her bedroom in Laure Fauvel's “Terreurs”, 2014, in Paris, France. An imaginative photographer has brought to life monsters that haunt children's nightmares. Armed with sticks, wands and swords the eight and nine year-olds appear to be getting the upper-hand against the villains. Parisian photographer Laure Fauvel, 22, said: I wanted the children not be victims and to fight the monsters. (Photo by Laure Fauvel/Barcroft Media)

Two Herens cows lock horns during the qualification round of the annual “Battle of the Queens” cow fight finals in Aproz, in the western Alpine canton of Valais May 5, 2013. Each year when taken to the alpine pastures, the cows test their strength and fight for the herd's leadership. The competition continues until a new queen has forced all the other cows to retreat. (Photo by Valentin Flauraud/Reuters)

Two men fight in San Jose, Costa Rica, during the Women's Day on March 8, 2014. (Photo by Jeffrey Arguedas/EFE/SIPA Press)