An officer is on fire as demonstrators clash with police during a protest against plans for new austerity measures on June 28, 2011 in Athens, Greece. Greece's largest labor unions have called for a 48-hour strike, while the Socialist government is beginning to push through legislation for cost cutting reforms. (Photo by Milos Bicanski/Getty Images)

Participants gather in the Union Square subway station during the annual No Pants Subway Ride on January 8, 2012 in New York City. The annual event is staged by the group Improv Everywhere which encourages people in dozens of cities worldwide to discard their pants while riding the subway. (Photo by Mario Tama/Getty Images)

Demonstrators confront riot police during clashes in central Brussels November 6, 2014. Tens of thousands of public and private sector workers, employees and trade union members demonstrated over austerity measures to be taken by the new Belgian government. (Photo by Francois Lenoir/Reuters)

The Resplendent Quetzal (Pharomachrus mocinno) is a bird in the trogon family. It is found from southern Mexico to western Panama (unlike the other quetzals of the genus Pharomachrus, which are found in South America and eastern Panama). It is well known for its colorful plumage.

Several new species of peacock spider – just a few millimetres long and featuring extraordinary colours – have been discovered in Western Australia and South Australia. Jürgen Otto, a biologist from Sydney, has been researching the arachnids since 2005, and has gained a significant following online with his footage. He believes there are now 48 confirmed species of peacock spider within the Maratus genus, found across Australia but particularly in Western Australia – and many more awaiting confirmation. Here: Maratus Tasmanicus, one of seven new species of peacock spiders studied by the Sydney biologist Jürgen Otto. (Photo by Jürgen Otto)

This Strange Russian Cartoon Shows Mario's Nasty Side and bogatyr or vityaz is a stock character in medieval East Slavic legends (byliny), akin to a Western European knight-errant.

A German Air Force Officer sits astride a dead boar outside a house where he is stationed near the Western Front, in this 1918 handout picture. This picture is part of a previously unpublished set of World War One (WWI) images from a private collection. The pictures offer an unusual view of varied and contrasting aspects of the conflict, from high tech artillery to mobile pigeon lofts, and from officers partying in their headquarters to the grim reality of life and death in the trenches. The year 2014 marks the centenary of the start of the war. (Photo by Reuters/Archive of Modern Conflict London)