A combination of four pictures shows participants dressed in superhero and heroic fantasy costumes posing during the second edition of the Hero Festival in Marseille, France, November 7, 2015. The festival is dedicated to American superhero comics, Japanese mangas, heroic fantasy characters and video games universes. (Photo by Jean-Paul Pelissier/Reuters)

Young Japanese women pose with a green bear costumed person during the 'Earth Parade 2015' in Tokyo, Japan, Saturday, November 28, 2015. Ahead of the U.N. climate change summit in Paris starting this week, about 1,000 citizens and environmental activists took to the streets of Tokyo on Saturday, calling for strong actions to combat global warming. (Photo by Franck Robichon/EPA)

Men dressed as “Krampuss” prepare to parade at Munich's Christmas market, December 13, 2015. Young single men will wear the traditional attires known as “Krampusse”, consisting of animal skins and masks, with large cow-bells to make loud and frightening noises and parade through the city. They follow “Saint Nicholas” from house to house in December each year to bring luck to the good and punish the idle. (Photo by Michael Dalder/Reuters)

A Colombian flower grower selects a rose for a bouquet ahead of Valentine's Day in Subachoque, February 2, 2015. Colombia is the world's second-largest flower exporter behind the Netherlands. The Andean country exports around 500 million flowers to the U.S. for Valentine's Day, according to the Colombia Flower Growers Association. (Photo by John Vizcaino/Reuters)

Brendan Fitzpatrick is a commercial photographer specialising in advertising and lifestyle photography. He also creates unique X-ray images marketed under the banner Invisible Light. Brendan is based in Sydney, Australia. (Photo by Brendan Fitzpatrick)

Most pet cats will become timid or defensive when outdoors, but not Millie – after being adopted by her mountain-climbing owner Craig Armstrong, Millie has become a feline hiking and mountain-climbing legend.

In this photo taken April 15, 2015, Clay Hielscher of Overbrook, Kan., poses for a photo in his home made Iron Man suit. While he enjoys building the battlesuits of his favorite super hero, Hielscher said the real reason he is so passionate about his pastime is his 11-year-old daughter, Kyrianna. They design and construct the suits together. (Photo by Chris Neal/AP Photo/The Topeka Capital-Journal)

Colleen Kelley, of Iowa City, Iowa, fixes the hat on her dog Bruce during judging at the 35th annual Drake Relays Beautiful Bulldog Contest, Monday, April 21, 2014, in Des Moines, Iowa. The pageant kicks off the Drake Relays festivities at Drake University where a bulldog is the mascot. (Photo by Charlie Neibergall/AP Photo)