A trade card from the 1880s depicts a Santa Claus figure in a bird-themed sleigh pulled by reindeer as they are about the land on a rooftop to deliver presents from the huge sack of gifts. Getty Images hide caption

Children light candles during an overnight vigil at a protest camp in Juarez, Mexico, outside the manufacturing plant for the American-owned printer company Lexmark. Mónica Ortiz Uribe/KJZZ hide caption

A New Year tree stands outside the Kremlin in Moscow, in 2008. Shown from right in the background are: the Kremlin's St. Nicholas Tower, the Historical Museum, and the monument to Soviet Marshal Georgy Zhukov. Mikhail Metzel/AP hide caption

Though most hoverboards are made safely, poor quality lithium-ion batteries could be the main culprit behind the recent safety scares. Christopher Furlong/Getty Images hide caption

In his 1942 mural The Underground Railroad, Woodruff shows slaves about to cross the Ohio River to freedom. Peter Harholdt/Copyright Talladega College hide caption

Dr. Irene Aguilar, a Democrat and Colorado state senator from Denver County, is also a medical internist and advocate of universal health care. She led this Denver rally in favor of the 2016 ballot measure. John Daley/Colorado Public Radio hide caption

Pope Francis caresses a baby at a charity in Rome on Friday. In keeping with his focus on the poor, he celebrated Mass at a soup kitchen at Rome's main train station. AP hide caption

In real life, Jonathan Sun is a Ph.D. candidate at MIT in the Department of Urban Studies + Planning. On Twitter, he's an alien who struggles with spelling and is baffled by human culture. Courtesy of Jonathan Sun hide caption

Film character BB-8 arrives at the world premiere of Star Wars: The Force Awakens at the TCL Chinese Theatre in Los Angeles on Dec.14. Jordan Strauss/Invision/AP hide caption