A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

The New World porcupine, family Erethizontidae, 1280 Gram born at 11 April 2015 Inventory in Zoo. Counting trade Fairs Weighing the Zoo is at 7 May 2015 too the 108 Birthday Zoo Hagenbeck Hamburg, Germany. (Photo by Imago/ZUMA Wire)

Members of staff makes last minute touch ups of wax figure Chewbacca, from Star Wars, on display at “Star Wars At Madame Tussauds” on May 12, 2015 in London, England. (Photo by Stuart C. Wilson/Getty Images)

Star Wars actors on the Cantina set at Star Wars Celebration: The Ultimate Fan Experience held at the Anaheim Convention Center on Thursday, April 16, 2015, in Anaheim, Calif. (Photo by Richard Shotwell/Invision/AP Photo)

Green Bay Packers' Johnathan Calvin rides a bike to NFL football training camp on July 27, 2017, in Green Bay, Wis. (Photo by Morry Gash/AP Photo)

Masked guests attend the “Grand Bal Christian Dior” during the Haute Couture Spring-Summer 2018 fashion collection presented in Paris, Monday, January 22, 2018. (Photo by Kamil Zihnioglu/AP Photo)

Schoolchildren perfom during celebrations to mark 35 years of Zimbabwe's Independence at the National sports stadium in Harare, Saturday, April 18, 2015. President Robert Mugabe, 91, the central figure in Zimbabwean politics 35 years after Independence from Britain, has led the country since 1980. (Photo by Tsvangirayi Mukwazhi/AP Photo)

A female Kurdistan Workers Party (PKK) fighter stands near a security position in Sinjar, March 13, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih /Reuters)