A photographer could bear-ly believe his eyes when a bear started waving at him. The friendly animal wandered to the front of his enclosure before sitting back in full view of zoo guests. He then lifts his powerful paw and excitedly waves in an almost human-like way at his new audience. The hilarious encounter was captured by keen photographer Andrey Slepnev, 31, while on a trip to Madrid Zoo, Spain on March 24, 2016. (Photo by Andrey Slepnev/Caters News)

An employee controls the arms of a manned biped walking robot “METHOD-2” during a demonstration in Gunpo, South Korea, December 27, 2016. It stands 13-feet (3,96 m) tall, weighs 1.3 tons and wields a pair of 286-pound (129,73 kg), motion-tracking metal arms. (Photo by Kim Hong-Ji/Reuters)

While most people head for cover at the first sign of a storm, this man runs straight toward it. Storm chaser and father of three Mike Olbinski is addicted to photographing extreme weather and regularly takes on tornadoes and supercell thunderstorms in a bid to capture extraordinary images. The photographer, from Phoenix, often travels hundreds of miles a day to reach the eye of a storm. He first became hooked on the unusual hobby almost a decade ago, following the birth of his daughter. Here: A stunning monsoon sunset coupled with intense lightning creating an amazing scene on August 26, 2017. (Photo by Mike Olbinski/Caters News Agency)

These images offer a rare glimpse of life within remote Brazilian tribes. Award winning photographer Ricardo, 47, said: “The pictures show the traditional way of life of these people who live in harmony with nature. The photos provide an overview of the contemporary situation of the indigenous people in Brazil”. Here: Bej indian in the Xingu river, state of Mato Grosso, Brazil on December 20, 2015 .(Photo by Ricardo Stuckert/Caters News Agency)

Alex Prager is an American art photographer and filmmaker based in Los Angeles. Her photographs primarily use staged actors, models and extras to create “meticulously designed mise en scène”, often described as film-like and hyperreal. “Alex Prager: Silver Lake Drive” is at the Photographers’ Gallery, London, 15 June – 14 October 2018. Here: The Big Valley, Susie and Friends, 2008. (Photo by Alex Prager Studio/Lehmann Maupin Gallery)

Debris fly into the air as foreign fishing boats are blown up by Indonesian Navy off Batam Island, Indonesia, Monday, February 22, 2016. Authorities on Monday sank dozens of fishing boats caught operating illegally in Indonesian waters as part of the country's campaign to battle illegal fishing. (Photo by M. Urip/AP Photo)

Two revelers dressed as toy soldiers gesture toward a police officer in a patrol car during the traditional carnival parade in Wuerzburg, Germany, 15 February 2015. Under the motto “Carnival Parade is cool” about 160 groups with over 3,000 members took part in one of the biggest carnival parades in southern Germany. (Photo by Daniel Karmann/EPA)

A street cleaner demonstrates his martial arts skills in front of a closed shop near Beijing's Tiananmen Square September 2, 2015 as the capital prepares for tomorrow's parade. (Photo by Damir Sagolj/Reuters)