“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

Challenger Bulgarian heavyweight boxer Kubrat Pulev (R) lies in the ring after being knocked down by Ukrainian WBA, WBO, IBO and IBF heavyweight boxing world champion Vladimir Klitschko (L), who celebrates with his brother Vitali (2nd L), as referee Tony Weeks checks on him after their title fight in Hamburg, November 15, 2014. World heavyweight champion Vladimir Klitschko knocked out Bulgarian challenger Kubrat Pulev with a fierce left hook in the fifth round on Saturday to retain his IBF title and end his opponent's unbeaten record. (Photo by Fabian Bimmer/Reuters)

An aerial view of the Atibainha dam, part of the Cantareira reservoir, during a drought in Nazare Paulista, Sao Paulo state November 18, 2014. Brazil's worst drought in 80 years has left the Cantareira system, that provides greater Sao Paulo with most of its water, with the lowest water level on record, with daily rationing becoming common in the region's smaller cities, according to the state authorities and the two main reservoirs serving metropolitan Sao Paulo, South America's largest city, could dry out by February if relief does not arrive in the upcoming rainy season. (Photo by Nacho Doce/Reuters)

What would superheroes do if they had a part time job? Well… besides fighting crime, the powers of most superheroes aren’t exactly very useful. Sure, Flash would make a great delivery boy, delivering the freshest pizza in the world, while Thor might turn out to be a great smith (though judging by the way he handles his mallet, it is very unlikely), but in the end of the day, all these things are pretty useless. It sure is hard being a superhero when you have no villains to catch; especially if the only superpower that you have is lighting yourself on fire. Reducing you to a mere job of being used as fuel for cooking grilled chicken. Besides, it’s not exactly useful for catching villains either, if you don't plan on burning them alive… (Photo by Chow Hon Lam)

Xie Guobiao (C), 11, tied to a pillar with a rope, cries as his grandmother (L) and younger sister look on at his home in Daohui village of Lishui, Zhejiang province May 7, 2014. Xie was diagnosed as mentally handicapped when he was young, but the family was not able to provide him with sufficient medical treatment because of poverty. At the age of six, Xie started to sneak out of his home when others were not looking, climbing on top of houses and smashing windows. Xie's family had to pay over 10,000 yuan ($1,606) in compensation to others for the damage he caused. Since then, the family has had to tie Xie up with a rope both at home and in public, they said. (Photo by William Hong/Reuters)

These are the explosive images of some of the world's most ASH-stonishing volcanic eruptions. Spectacular snaps capture lava spewing down the side of Kilauea, ash spitting from craters and plumes of smoke rising thousands of feet in the air. Russian non-profit AirPano travel the globe taking the breath-taking panoramic images, compiled in this series displaying their most stunning volcanic shoots. Included in the set – which spans four continents – are images from across the United States, Iceland, Russia, Ethiopia and Indonesia. To capture the 360-degree images, AirPano photographers spend around two hours in a helicopter, sending out drones to capture the action below. Here: Volcano Plosky Tolbachik, Kamchatcka, Russia. (Photo by Airpano/Caters News)

“Daredevil photographer Krystle Wright suffered a catalogue of injuries after an accident on a shoot in Pakistan. The 26-year-old was left with internal bruising, tendon damage, two fractures, a torn ligament and 10 stitches above her eye following the horrific fall in the Himalayas. Wright took to the air on a dual paraglider and flew at a stomach-churning 18,000 feet to capture the incredible images. But as she neared the end of her trip Wright hit a bolder and blacked out following a bad take-off. The keen photographer, from Queensland, Australia, has travelled the world shooting some of the most awe-inspiring extreme sport stunts”. – Caters News. Photo: Screenshot of Krystle and Hernan, taken on a foot mounted GoPro. (Photo by Krystle Wright/Caters News)

“Models decorated with glow-in-the-dark paint manage to stand out in a new series of pictures shot in the dark. Its well known that capturing beautiful photos without natural light is a tricky undertaking even for the most talented photographers but Hid Saib Neto has found a way to make the most of the darkness. The 26-year-old Brazilian photographer covered the group of models in neon paint before illuminating them with just a single ultra-violet light”. – Caters News. Photo: A model wearing the neon make up. (Photo by Hid Saib Neto/Caters News)