These young sloth bears hitch a ride on their mother's back as she forages for food in the Ranthambhore Tiger Reserve in the Indian state of Rajasthan in May 2023. (Photo by Aditya Singh/Solent News)

Zappa, a toothless 15-year-old Italian greyhound that looks surprisingly like Sid the Sloth from the animated movie Ice Age, is redefining dog beauty. Owners Sadie and Rosalie Millen, of Pewaukee, Wisconsin, say that Zappa started sticking her tongue out a few years ago when she lost her teeth.

Enya Kim from the Natural History department at auctioneers Bonhams & Butterfields stands in front of one of the world's largest set of shark jaws comprised of about 180 fossil teeth from the prehistoric species, Carcharocles megalodon, which grew to the size of a school bus, at the Venetian Resort Hotel Casino September 30, 2009 in Las Vegas, Nevada. (Photo by Ethan Miller/Getty Images)

Brown bear cubs eat out of garbage bins at a residential area near the forest in Sarikamis district of Kars, Turkiye on May 30, 2023. (Photo by Huseyin Demirci/Anadolu Agency via Getty Images)

People look at a black bear at the Chengdu zoo amid the coronavirus outbreak on March 26, 2020 in Chengdu, Sichuan Province of China. (Photo by Wang Lei/China News Service via Getty Images)

A man dressed as a bear and wearing a protective face mask amid the outbreak of the coronavirus disease (COVID-19) stands in front of a fountain in central Kyiv, Ukraine on August 11, 2020. (Photo by Valentyn Ogirenko/Reuters)

A polar bear fast asleep at London Zoo. (Photo by Fox Photos/Getty Images). 1961