Shell, which is the replica of the biggest detonated Soviet nuclear bomb AN-602 (Tsar-Bomb), is on display in Moscow, Russia, August 31, 2015. The shell is part of an exhibition organized by the state nuclear corporation Rosatom. (Photo by Maxim Zmeyev/Reuters)

A performer in traditional costume waits for her turn to go on stage at Longtan park as the Chinese Lunar New Year, which welcomes the Year of the Rooster, is celebrated in Beijing, China January 29, 2017. (Photo by Damir Sagolj/Reuters)

A girl watches an acrobatic performance at the Longtan park as the Chinese Lunar New Year, which welcomes the Year of the Monkey, is celebrated in Beijing, China February 9, 2016. (Photo by Damir Sagolj/Reuters)

A boy dressed as Lord Krishna is pictured while Hindu devotees march on the streets to celebrate Janmashtami festival, which marks the birth anniversary of Lord Krishna, in Dhaka, August 14, 2017. (Photo by Mohammad Ponir Hossain/Reuters)

Eagle Prime (MK3), a giant robot by MegaBots Inc. which manufactures giant piloted humanoid fighting robots headquartered in Berkeley, California on October 18, 2017. (Photo by Courtesy Michael Mauldin/Reuters/MegaBots Inc)

A mahout guards the elephants during the annual Vrischikolsavam festival, which features a colourful procession of decorated elephants along with drum concerts, at a temple in Kochi, India, November 18, 2017. (Photo by Sivaram V/Reuters)

The driver of a Maerlitram (fairy tram), dressed as a Santa Claus, walks past a car which crashed into the tram in Zurich, Switzerland December 7, 2017. (Photo by Angelika Gruber/Reuters)