A member of Red Noses Clowndoctors entertains migrants before their departure to Austria at a registration center in Dobova, Slovenia, December 27, 2015. (Photo by Srdjan Zivulovic/Reuters)

Goyo, an eight-month-old mini pig, plays with a dog in Mexico City, December 21, 2015. Mini pigs can grow to about 30 kg (66.1 lbs) in weight and about 35 cm (1.1 ft) in height, according to the company Mini Pigs Mexico. The company says that the mini pigs' popularity as pets is growing and around 300 are sold every year in Mexico, with prices ranging from $350 to $1,600. (Photo by Edgard Garrido/Reuters)

Graffiti saying “justice” partially seen above flood waters in Asuncion, December 27, 2015. More than 100,000 people have had to evacuate from their homes in the bordering areas of Paraguay, Uruguay, Brazil and Argentina due to severe flooding in the wake of heavy summer rains brought on by El Nino, authorities said on Saturday. (Photo by Jorge Adorno/Reuters)

A man dressed as Santa Claus sits at a bus stop before an annual race in Belgrade, Serbia December 27, 2015. (Photo by Marko Djurica/Reuters)

Afghan militia men stand near to the dead body of a beheaded Islamic State group loyalist in the Achin district of Nangarhar province east of Kabul, Afghanistan, Sunday, December 27, 2015. An Afghan official says fighters for the Islamic State group and a militia controlled by a prominent lawmaker have beheaded a total of eight men in tit-for-tat revenge killings in the eastern border province of Nangarhar. (Photo by Mohammad Anwar Danishyar/AP Photo)

Black-headed gulls sit on pickets at a riverside in Tokyo, Japan, December 27, 2015. (Photo by Toru Hanai/Reuters)

Jassen Todorov, 40, from San Francisco is a professor of music at San Francisco State University, but he took to helicoptering in his spare time. While he was content to keep the panoramic views he witnessed to himself, Todorov has now paired his passion for flying with photography to capture some of the United States’ undiscovered vistas. Here: Grand Prismatic Spring, Yellowstone, Wyoming. (Photo by Jassen Todorov/Caters News)

An airplane crosses a nearly full-moon on its way to Los Angeles International Airport near Whittier, Calif., Thursday, December 24, 2015. Not since 1977 has a full moon dawned in the skies on Christmas. (Photo by Nick Ut/AP Photo)