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)

A leopard runs to at people as they run for cover in Katmandu, Nepal, on April 10, 2013. According to reports, 15 people were injured including three policemen and two officials from the Department of Forest. The leopard was later killed with the help of Nepalese policemen and local media. (Photo by Niranjan Shrestha/Associated Press)

ATTENTION: VISUAL COVERAGE OF SCENES OF INJURY AND DEATH

These little grizzly bear cubs had fun making a real splash when their mum took them for a dip to learn how to fish. Kamchatka, Russia. (Photo by Marco Mattiussi/Solent News & Photo Agency)

A Syrian boy receives treatment at a hospital in the regime-held part of Aleppo on October 13, 2016. Syrian state television said four children were killed by rebel rocket fire on a school in a western regime-held neighbourhood. (Photo by George Ourfalian/AFP Photo)

in Qayyarah, about 31 miles (50 km) south of Mosul, Iraq, Sunday, October 23, 2016.in Qayyarah, some 50 kilometers south of Mosul, Iraq, Sunday, Oct. 23, 2016. Islamic State fighters torched a sulfur plant south of Mosul, sending a cloud of toxic fumes into the air that mingled with oil wells the militants had lit on fire to create a smoke screen. (Photo by Marko Drobnjakovic/AP Photo)

A Hindu pilgrim feeds biscuits to an ox to seek blessing before heading for an annual trip to Sagar Island for the one-day festival of “Makar Sankranti”, in Kolkata, India January 10, 2017. (Photo by Rupak De Chowdhuri/Reuters)

Fans gather to watch a FIFA World Cup Russia 2018 football match between Brazil and Costa Rica on a giant screen at Alzirao neighborhood in Rio de Janeiro, Brazil on June 22, 2018. (Photo by Carl De Souza/AFP Photo)

Photographers take photographs of the Large Air Tanker (LAT) C-130 Hercules, also known as “Thor”, as it drops a load of around 15,000 litres during a display by the Rural Fire Service ahead of the bushfire season at RAAF Base Richmond Sydney, Australia, September 1, 2017. (Photo by David Gray/Reuters)