Opossums on their mothers back at a game reserve in Central Minnesota, USA, on September 2, 2013. (Photo by Caters News Agency)

Greyhounds with stuffed and sprung model monkeys strapped to their backs before a hurdle race at Wellinborough. (Photo by E. Bacon). 21st April 1928

A mouse rides on the back of a frog in floodwaters in the northern Indian city Lucknow June 30, 2006. (Photo by Pawan Kumar/Reuters)

A man sits at the back of his car in the city centre of Yangon on September 15, 2023. (Photo by Sai Aung Main/AFP Photo)

Tank Chair is a custom off-road wheelchair that can go anywhere outdoors. Tank Chair conquers streams, mud, snow, sand, and gravel, allowing you to get back to nature. Using rubber tracks and high-torque electric motors, Tank Chair will take you anywhere and back.

A Pakistani labourer carries bricks on his back at a construction site at a residential area in Islamabad on March 29, 2017. (Photo by Aamir Qureshi/AFP Photo)

An elephant enjoys its back being scrubbed by the keeper on March 1, 1950. (Photo by Fox Photos/Getty Images)

A tiger is painted on the backs of three models at the Three Lanes and Seven Alleys on January 3, 2012 in Fuzhou, China. (Photo by ChinaFotoPress/ChinaFotoPress)