A four-legged robot dog called SPOT patrols a park as it undergoes testing to be deployed as a safe distancing ambassador, following the coronavirus disease (COVID-19) outbreak, in Singapore on May 8, 2020. (Photo by Edgar Su/Reuters)

Andrej Ciesielski dangels his legs off the side of a building overlooking Times Square, New York City. (Photo by Andrej Ciesielski/Caters News Agency)

Nature, singles winner: Frogs with their legs severed struggle to the surface, surrounded by frogspawn, after being thrown back into the water in Covasna, Romania. (Photo by Bence Mate/World Press Photo 2019)

Alee Harrison, 13, wears the tv series “Doctor Who” on her legs as she works on a painting for Operation Blue Pride. (Photo by Greg Lovett/The Palm Beach Post)

Pooh, a one-year-old cat, who lost his hind legs in an accident and has been given bionic paws, walks in a vet clinic in Sofia on January 31, 2017. Pooh, who is thought to have lost his legs in a car or train accident last April, is back on the prowl thanks to Bulgarian veterinary surgeon Vladislav Zlatinov. He is the first vet in Europe to successfully apply the pioneering method of Irish neuro-orthopaedic surgeon Noel Fitzpatrick, who shot to fame in 2009 when making Oscar the first bionic cat by fitting him with new hind legs in Britain. (Photo by Nikolay Doychinov/AFP Photo)

In this April 4, 2017 photo, Zoologist Martha Llanes caresses baby chimpanzee Anuma II, left, while Ada hangs on to her leg, at Llanes' apartment in Havana, Cuba. She has forgiven them every transgression. It's hard to stay angry at a baby chimpanzee when it clambers up your leg and into your arms and plants a kiss on your cheek in a plea for forgiveness. (Photo by Ramon Espinosa/AP Photo)

Sakakibara Kikai's engineer Go Sakakibara poses with the bipedal robot Mononofu during its demonstration at its factory in Shinto Village, Gunma Prefecture, Japan on April 12, 2018. Developed at Sakakibara Kikai, a maker of farming machinery, LW-Mononofu is a 28-feet tall, two-legged robot weighing in at more than 7 tonnes. It contains a cockpit with monitors and levers for the pilot to control the robot's arms and legs. (Photo by Kim Kyung-Hoon/Reuters)

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/AP Photo)