“In anatomy, heterochromia refers to a difference in coloration, usually of the iris (but also of hair or skin). Although infrequently seen in humans, complete heterochromia is more frequently observed in other species, where it almost always involves one blue eye”. – Wikipedia (Photo by StooMathiesen)

A chevrotain or mouse deer feeds in its enclosure at Zurich Zoo, Zurich, Switzerland, October 17, 2012. (Photo by Patrick B. Kraemer/AP)

The goats are known to be good climbers, but this one is taking the climbing thing to a whole new level. It clambered on the tip of its owner’s stick, as a part of the roadside performance for a quick coin, on the outskirts of Faisalabad, Pakistan, November 5, 2012. (Photo by Fayyaz Hussain/Reuters)

A large Pacific sideband snail slowly crosses a rain wet road in rural Douglas County, Oregon near Elkton on Sunday, December 2, 2012. The moisture loving snail should be very content with the recent heavy rains in southwestern Oregon and northern California. (Photo by Robin Loznak)

A Aldabra Tortoise receives a Christmas treat at Taronga Zoo on December 14, 2012 in Sydney, Australia. Taronga Zoo celebrated Christmas early giving Christmas-themed environmental activities to the Zoo's Giraffes, Sun Bears, Meerkats, Aldabra Tortoise and Cockatoos providing a wonderful natural display for Zoo visitors. (Photo by Lisa Maree Williams)

A mountain jerboa, which is taken under protection after his mother dies, is seen at Yuzuncu Yil University Wild Animal Protection and Rehabilitation Center in Van, Turkiye on June 24, 2022. (Photo by Mesut Varol/Anadolu Agency via Getty Images)

Visitors look at a plastinated gorilla on the opening day at the Body World Animals exhibition at the Cologne Zoo on April 15, 2011 in Cologne, Germany. The exhibition is by Gunther von Hagens, who uses a special process to preserve real bodies, whether animal or human, in order to display the inner organs, muscles and other physical elements. The exhibition will be open to the public until September 30.

Cosplay enthusiasts Alex Lawson, 20, attends the North East Manga and Anime Convention (NemaCon) dressed as Hunni Sempai at Middlesborough Town Hall on June 18, 2011 in Middlesbrough, England. Hundreds of Manga, Anime and Cosplay enthusiasts gathered for NemaCon 2011. Cosplay is short for Costume Play where players dress and perform roles from Japanese culture, Anime and Manga art characters. Many subcultures have also evolved inspired by video games, American cartoons and comics. (Photo by Christopher Furlong/Getty Images)