A tattoo of Captain America drawn by artist Sean Karon on the leg of client Ron Raucci at the Hampton Roads Tattoo Festival in Virginia, on March 2, 2012. The tattoo was completed from start to finish in one five-and-a-half hour session and won the prestigious “tattoo of the day” contest. (Photo by Jason Reed/Reuters)

In this Tuesday, June 18, 2013 photo, Zita, a liger – half-lioness, half-tiger – carries her one month-old liliger cub in the Novosibirsk Zoo. The cub's father is a lion, Sam. (Photo by Ilnar Salakhiev/AP Photo)

An adult chimp plays with a young chimp at Chimp Haven in Keithville, La., Monday, February 18, 2013. One hundred and eleven chimpanzees will be coming from a south Louisiana laboratory to Chimp Haven, the national sanctuary for chimpanzees retired from federal research. (AP Photo/Gerald Herbert)

Children react as a carnivorous theropod known as the Australovenator dinosaur walks through crowds along the Southbank, in London, Monday, February 18, 2013. The dinosaur is one of many that can be visited at the Erth's Dinosaur Petting Zoo, visiting from Australia, the creatures can be touched and fed at the Southbank Centre. (Photo by Kirsty Wigglesworth/AP Photo)

The Tsaatan people are one of the world’s last groups of nomadic reindeer herders and they live in Khövsgöl Aimag in northern Mongolia. They are originally from across the border in what is now the Tuva republic of Russia. (Photo by Pascal Mannaerts/Rex Feature/Shutterstock)

People take pictures of the Tribute in Light while it is illuminated next to the Statue of Liberty (C), One World Trade Center and the Empire State Building during events marking the 14th anniversary of the 9/11 attacks on the World Trade Center in New York September 11, 2015. (Photo by Eduardo Munoz/Reuters)

An agent of the OIPR, one of the government agencies charged with managing protected land, stands next to cocoa trees inside Mont Peko National Park in Duekoue department, western Ivory Coast August 18, 2015. (Photo by Luc Gnago/Reuters)

A s*x worker (C) stages a performance to denounce what they say is abuse and social stigma against them in Madrid, Spain, October 14, 2015. Placard reads "Prostitutes are the ones that make the streets dirty". (Photo by Andrea Comas/Reuters)