Clay "caganers" representing Spanish Prime Minister Mariano Rajoy (2nd L), Podemos's candidate Pablo Iglesias (R), Socialist Party (PSOE) leader Pedro Sanchez (2nd R) and Ciudadanos party leader Albert Rivera (L) are seen on display at the Santa Llucia Christmas market in central Barcelona, Spain, December 16, 2015. Catalans hide “caganers” or defecators, in Christmas Nativity scenes to let friends hunt for them during Christmas celebrations. The “caganers”, which symbolise defecation and fertilization of the earth, are believed to bring prosperity and luck for the coming year. (Photo by Albert Gea/Reuters)

A dinosaur robot produced by Tyco Electronics Japan G.K. is controlled by a smartphone at CEATEC (Combined Exhibition of Advanced Technologies) Japan 2014 held at at Makuhari Messe in Chiba, east of Tokyo, Japan, 07 October 2014.With a Sharp Aquos ZETA mobile phone model, users can make the 6.5-meter (21 feet, 4 inches) long, 2.1-meter (6 feet, 11 inches) tall dinosaur robot to walk forward and backward, jump, move its head, hands and legs up and down, left and right, open and close its mouth by touching the screen panel and make it bark by shaking the handheld. (Photo by Kimimasa Mayama/EPA)

Skulls are seen at the witch doctor kiosk during the day of offerings to the “Pachamama” (Mother Earth) in El Alto, Bolivia, August 1, 2016. Pachamama is a goddess revered by the indigenous people of the Andes. She is also known as the earth/time mother. In Inca mythology, Pachamama is a fertility goddess who presides over planting and harvesting, embodies the mountains, and causes earthquakes. (Photo by David Mercado/Reuters)

“An egg case or egg capsule, colloquially known as a mermaid's purse or devil's purse, is a casing that surrounds the fertilized eggs of some sharks, skates, and chimaeras”. – Wikipedia. Photo: OBX Skate (Raja eglanteria) Egg Case – Mermaid's Purse. (Photo by altereye1)

Growing cities, overuse of fertilizers and factory wastewater have degraded China's water supplies to the extent that half the nation's rivers and lakes are severely polluted. China aims to spend $850 billion to improve filthy water supplies over the next decade, but even such huge outlays may do little to reverse damage caused by decades of pollution and overuse in Beijing's push for rapid economic growth. Photo: Fishermen row a boat in the algae-filled Chaohu Lake in Hefei, Anhui province, June 19, 2009. (Photo by Jianan Yu/Reuters)

A masked Bulgarian dancer takes part in the second competition day of the 24th International Festival of Masquerade Games “Surva” in the town of Pernik, Bulgaria Saturday, January 31, 2015. Some 5,000 people are expected to take part in the three-day festival devoted to an ancient Bulgarian pagan rite. Surva is performed by costumed men, some in sheepskin, or other colorful garments, bells and masks, who walk around and dance to scare away the evil spirits, in hope to provide a good harvest, health, fertility, and happiness. (Photo by Valentina Petrova/AP Photo)

People at a Czech Stop look at a cloud of smoke rising from the explosion in West, Texas, April 17, 2013. (Photo by Andy Bartee via Dallas Morning News/MCT)

This undated handout picture made available on February 3, 2016 and provided by Russia's punk band Рussy Riot shows Рussy Riot frontwoman Nadezhda Tolokonnikova performing in the band's new music video titled “Chaika” in Moscow. Russian punk band Рussy Riot, which became a symbol of resistance for a church performance slamming President Vladimir Putin, released a new protest song on February 3 mocking a senior official for alleged corruption. Titled “Chaika”, the satirical song and accompanying video take aim at prosecutor general Yury Chaika, whose two sons have been accused of using their father's position to accrue large fortunes. (Photo by Andrey Noskov/AFP Photo/Russian Punk Band Рussy Riot)