Two female revelers engage in a beer drinking contest in the Hacker Pschorr tent on the first day of the 2017 Oktoberfest beer fest on September 16, 2017 in Munich, Germany. Oktoberfest is the world's largest beer celebration and typically draws over six million visitors over its three-week run. Oktoberfest includes massive beer tents, each run by a different Bavarian brewer, as well as amusement rides and activities. (Photo by Philipp Guelland/Getty Images)

Horse riders perform with guns during the El-Jadida International Horse Show in El-Jadida, south of Casablanca, Morocco, October 15, 2016. (Photo by Youssef Boudlal/Reuters)

Sara Moni, dressed as the World of Warcraft's Sinestra, poses for photographers on day three of the Comic-Con International held at the San Diego Convention Center Saturday July 23, 2016 in San Diego. (Photo by Denis Poroy/Invision/AP Photo)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

Whether they are the hunter or the hunted, these camouflage animals show natures incredible ability to blend in with its surroundings. Pictured perfectly concealed against their natural environment, the stunning pictures show the amazing lengths some animals will go to to stay out of sight. Here: The camouflage mappet moth looks like a fall lead in Switzerland. (Photo by Thomas Marent/Caters News/Ardea)

A zoo employee carries three-month-old female giant panda cub, born to mother Liang Liang and father Xing Xing, on display to the public for the first time at the national zoo in Kuala Lumpur, Malaysia, November 17, 2015. (Photo by Olivia Harris/Reuters)

A bonnet macaque sits on consecrated idols of snakes during the Nag Panchami festival inside a temple on the outskirts of Bengaluru, India, August 19, 2015. (Photo by Abhishek N. Chinnappa/Reuters)

In this September 16, 1983 file photo, actor and bodybuilder Arnold Schwarzenegger shows off his new U.S. citizenship papers as Maria Shriver, daughter of Sargent and Eunice Shriver, looks on at the Shrine Auditorium in Hollywood, Calif. (Photo by Wally Fong/AP Photo)