Moana Mason, 8, participates in the People's Summit event on Guajara Bay during the COP30 U.N. Climate Summit, Wednesday, November 12, 2025, in Belem, Brazil. (Photo by Joshua A. Bickel/AP Photo)

Filipino mermaid swimming teacher Genevieve Reyes (C) has her tail adjusted by students during a lesson by the Philippines Mermaid Swimming Academy in a private swimming pool in Makati, Manila, Philippines, 15 June 2013. The Philippine Mermaid Swimming Academy (PMSA) was created in 2012 in Boracay by Normeth Preglo of The Philippines and US swimming instructor Djuna Rocha. The swimming lessons were brought to Manila in April 2013. The price for a two-hour class is 37 US dollars. (Photo by Dennis M. Sabangan/EPA)

Yoandri Hernandez Garrido, 37, proudly displays his 12 fingers in Baracoa, Guantanamo province, Cuba. His condition, known as polydactyly, is relatively common, but it's rare for extra digits to be so perfect.

Polydactyly or polydactylism (from Ancient Greek πολύς (polus) "many" + δάκτυλος (daktulos) "finger"), also known as hyperdactyly, is a congenital physical anomaly in humans, dogs, and cats having supernumerary fingers or toes. Polydactyly is the opposite of oligodactyly (fewer fingers or toes).

A Ugandan soldier, part of the 9,000-strong African Union Mission in Somalia, (AMISOM) walks through the Banadir soccer stadium on August 15, 2011 in Mogadishu, Somalia. The stadium, Somalia's largest soccer facility, had been under control by Islamic extremist Shabab militants for the past two years until they withdrew from the capital more than a week ago. (Photo by John Moore/Getty Images)

Students at the Cuba's National Ballet School (ENB) watch a class from outside the classroom in Havana, Cuba, October 12, 2016. Catherine Conley, the first American full-time student at Cuba's prestigious National Ballet School, hopes to gain an edge back home by learning the powerful Cuban style with its dazzling turns and jumps. (Photo by Alexandre Meneghini/Reuters)

Actor John Travolta (L) and recording artist Lady Gaga attend Interscope's Grammy After Party with Lady Gaga at the Peppermint Club on February 12, 2017 in Los Angeles, California. (Photo by Christopher Polk/Getty Images for Interscope)

Bjorn, aged 5, smiles as he poses with a Owl butterfly during an event to launch the Sensational Butterflies exhibition at the Natural History Museum in London, Britain March 23, 2016. The exhibition opens to the public on March 24 and runs until September 11. (Photo by Dylan Martinez/Reuters)

A macaque crosses a pedestrian overpass in Hong Kong, China, 08 November 2021. According the Agriculture, Fisheries and Conservation Department, AFCD, the total population of wild monkeys in Hong Kong is about 1,800, distributed in 30 social troops. (Photo by Jerome Favre/EPA/EFE)