A young Hindu priest crawls under a cow as part of worship rituals during Tihar festival in Kathmandu, Nepal, Sunday, October 30, 2016. Cows are considered sacred to Hindus and are worshipped during Tihar festival, one of the most important Hindu festivals dedicated to the Goddess of wealth Laxmi. (Photo by Niranjan Shrestha/AP Photo)

Each year Nikon Small World recognizes the excellence of photography taken under the microscope. The contest showcases the beauty and complexity of life. Anyone interested in microscopy and photography can enter the contest and in its 42nd year, Nikon Small World received 2,000 entries from 70 countries. Here: 11th Place; Scales of a butterfly wing underside (Vanessa atalanta). (Photo by Francis Sneyers/Nikon's Small World 2016)

“People of the River”. This is a Karo tribe family; father, mother, two sisters and two brothers. The tribe, who live along the Omo River in east Africa, incorporate rich symbolism into their rituals by using ornate body art, headdresses and body scarification to express beauty and significance. (Photo by Jatenipat Ketpradit/International Portrait Photographer of the Year)

Ziripot, a traditional figure stuffed with straw, is helped up during Carnival celebrations in the Navarran village of Lantz, on February 16, 2015. (Photo by Vincent West/Reuters)

An Indian resident assists a dog as he wades through floodwaters in Ahmedabad on July 30, 2014. Rains lashed Ahmedabad and many regions of India's western Gujarat state, wth the Indian Metrological Department warning of heavy rains for the next 48 hours. (Photo by Sam Panthaky/AFP Photo)

Female bodybuilders compete in the annual Muscle Beach Championship bodybuilding and bikini competition at Venice Beach, California on September 7, 2015. Muscle beach Venice is one of two historic bodybuilding locations and took over as the most famous spot when the nearby Santa Monica Muscle beach was shutdown due to overcrowding. California Governor and actor Arnold Schwarzenegger used to be a regular amongst the many famous bodybuilders and actors who have trained there and still makes an occasional appearance. (Photo by Mark Ralston/AFP Photo)

A plane carrying a wing walker crashed at an air show and exploded into flames Saturday, killing the pilot and stunt walker, authorities said. The crash of the 450 HP Stearman happened at around 12:45 p.m. at the Vectren Air Show near Dayton in front of thousands of horrified spectators. No one else was hurt.

Photo: A wing walker performs at the Vectren Air Show just before crashing, Saturday, June 22, 2013, in Dayton, Ohio. The crash killed the pilot and the stunt walker instantly, authorities said. (Photo by Thanh V. Tran/AP Photo)

This is the amazing moment a heroic hippo saved a gnu from certain death. After being bitten by a crocodile, the large antelope is seen being dragged slowly under the water. But in a miraculous turn of events, a nearby hippo is seen making its way across the water to help the animal in its hour of need. Photo: One of the biggest hippos protects the gnu as it makes its way back to the shoreline, guarding it from any further attacks. (Photo by Vadim Onishchenko/Caters News)