Wrestler Kairi Hojo jumps at her opponent Mieko satomura during their Stardom female professional wrestling show at Korakuen Hall in Tokyo, Japan, July 26, 2015. Professional women's wrestling in Japan means body slams, sweat, and garish costumes. But Japanese rules on hierarchy also come into play, with a culture of deference to veteran fighters. The brutal reality of the ring is masked by a strong fantasy element that feeds its popularity with fans, most of them men. (Photo by Thomas Peter/Reuters)

79 year old Constance Ngubane spars in the ring as she takes part in a “Boxing Gogos” (Grannies) training session hosted by the A Team Gym in Cosmo City in Johannesburg on September 19, 2017. The grandmothers, many of whom are over 70 have been training with coach Claude Maphosa and claim that they no longer suffer from the ailments they had before, and are stronger than ever. The grannies travel from all over Cosmo City for the twice weekly sessions. Coach Maphosa is in the process of planning events in other areas for grannies who have been inspired by the story, to join in. (Photo by Gulshan Khan/AFP Photo)

Challenger Bulgarian heavyweight boxer Kubrat Pulev (R) lies in the ring after being knocked down by Ukrainian WBA, WBO, IBO and IBF heavyweight boxing world champion Vladimir Klitschko (L), who celebrates with his brother Vitali (2nd L), as referee Tony Weeks checks on him after their title fight in Hamburg, November 15, 2014. World heavyweight champion Vladimir Klitschko knocked out Bulgarian challenger Kubrat Pulev with a fierce left hook in the fifth round on Saturday to retain his IBF title and end his opponent's unbeaten record. (Photo by Fabian Bimmer/Reuters)

Talini (R), a 9-month old 160-pound polar bear cub, swims with her mother Barle at the Detroit Zoo's Artic Ring of Life exhibit August 25, 2005 in Royal Oak, Michigan. Talini's birth was the first polar bear birth at the Detroit Zoo in fifteen years. Her mother Barle was wild born and was rescued by the Detroit Zoo from a circus in Puerto Rico in 2002. (Photo by Bill Pugliano/Getty Images)

Three years ago, Shane Willmott wowed the world with his surfing mice. Now, the Australian has taken on a new challenge - training his radical rodents to skateboard. Mr Willmott, who lives in the Gold Coast area of eastern Australia, near Brisbane, has even built his furry friends a mini skate park. Fearless mice Harvey and Pedro take on ramps, half-pipes and even a deadly ring of fire.

Rose-ringed Parakeets roost in a copse in Wormwood Scrubs Park on December 6, 2011 in London, England. Approximately 2,500 parakeets roost in the copse at the centre of Wormwood Scrubs which has been designated by English Nature as an important site of natural significance. (Photo by Oli Scarff/Getty Images)

Muay Thai boxer Nong Rose Baan Charoensuk, who is transgender, trains at a gym in Buriram province, Thailand, July 3, 2017. Born Somros Polchareon, Rose said she identified as a woman at an early age and began wearing makeup and a sports bra in the ring.(Photo by Athit Perawongmetha/Reuters)

Wrestler Kairi Hojo jumps at her opponent Mieko satomura during their Stardom female professional wrestling show at Korakuen Hall in Tokyo, Japan, July 26, 2015. Professional women's wrestling in Japan means body slams, sweat, and garish costumes. But Japanese rules on hierarchy also come into play, with a culture of deference to veteran fighters. The brutal reality of the ring is masked by a strong fantasy element that feeds its popularity with fans, most of them men. (Photo by Thomas Peter/Reuters)