A young exhibitor arrives with her kitten on a lead at the National Cat Club show at Crystal Palace, London. (Photo by Fox Photos/Getty Images). 2nd December 1931

Baby clouded leopards, born early in March 2015, are presented by zoo keepers at the Olmense Zoo in Olmen, Belgium, April 16, 2015. The clouded leopard is an endangered species with only some 10,000 specimen remaining on earth, said Robby Van der Velden, a biologist at the Olmense Zoo. (Photo by Yves Herman/Reuters)

“The pygmy hippopotamus (Choeropsis liberiensis or Hexaprotodon liberiensis) is a large mammal native to the forests and swamps of western Africa (the specific name liberiensis means “of Liberia”, as this is where the vast majority live). The pygmy hippo is reclusive and nocturnal. It is one of only two extant species in the Hippopotamidae family, the other being its much larger cousin the common hippopotamus”. – Wikipedia

Photo: Monifa, a one month old baby Pygmy Hippopotamus takes a morning bath at Taronga Zoo on November 7, 2008 in Sydney, Australia. Monifa is the first Pygmy Hippopotamus to be born at Taronga Zoo in the past twenty three years. (Photo by Sergio Dionisio/Getty Images)

A US Marine feeds an orphan kitten found after a heavy mortar barrage near “Bunker Hill” during the Korean War. (Photo by Sgt Martin Riley/Getty Images). 1953

Two brown bear cubs born at Whipsnade Zoo. (Photo by Evening Standard/Getty Images). 1970

A zoo keeper feeds Diego, a three month old howler monkey, which is reared at Edinburgh Zoo, July 29, 2008 in Scotland. (Photo by Jeff J. Mitchell/Getty Images)

A baby bush-baby in a set of scales at London Zoo shortly after birth. (Photo by Fox Photos/Getty Images). 10th August 1938

An adorable baby koala is seen enjoying a snooze after a traumatic start to life. The baby koala, nicknamed “Blondie Bumstead”, is being cared for by a volunteer from the Ipswich Koala protection society in Queensland after her mother was killed by a dog. Blondie, who was named for her light fur, was given just a 50-50 chance of pulling through after the attack. But after a course of antibiotics and some tender loving car from volunteer Marilyn Spletter she has now been given a clean bill of health. According to Marilyn she has hand-reared around 40 baby koalas but says that Blondie, who will be released back into the wild after 15 months, is one of her favourites. She said: “She's got a little character all of her own and she knows what she wants and what she doesn't. When she's stressed I kiss her on the nose or I rub my nose on hers and it relaxes her”. (Photo by Jamie Hanson/Newspix/REX Features)