An Amur tiger walks across a passageway after a news conference at the Philadelphia Zoo, Wednesday, May 7, 2014, in Philadelphia. The see-through mesh pathway called Big Cat Crossing is part of a national trend called animal rotation that zoos use to enrich the experience of both creatures and guests. (Photo by Matt Slocum/AP Photo)

From the 1940s through the 1960s, the Alfred Mainzer Company of Long Island City, NY published a series of linen and photochrome humorous cat postcards illustrated by Eugen Hartung (or Hurtong) (1897–1973), sometimes referred to as “Mainzer Cats”. These postcards normally illustrate settings that are filled with action, often with a minor disaster just about to occur. While the dressed cats were by far the most popular and most plentiful cards, Hartung also painted other dressed animals – primarily mice, dogs, and hedgehogs.

When Dutch photographer Marcel Heijnen moved to Hong Kong, the territory’s shop cats instantly caught his eye. While the “feline emperors” are the stars, his shots also offer insights into Hong Kong’s wares, from dried fish to paper. Here: Hong Kong Shop Cats #17. (Photo by Marcel Heijnen/Blue Lotus)

Full-time feline photographer Andrew Marttila from Washington, D.C., captured blissful expressions of various cats on catnip, which he used to compile a book, “Cats on Catnip”. The photographer dedicated his time to capturing the euphoric expressions of kitties high on catnip – and the results are absolutely hilarious. (Photo by Andrew Marttila/Caters News Agency)

A cat Loki with a pair of distinctive fangs has quickly become one of the most famous felines on Instagram thanks to evil-looking face. Loki, who now has more than 23,000 followers online, was adopted from a cat shelter by her owner Kaet, who explained on in a posting that she knows very little about the cat’s distinctive appearance. Adopted from a cat shelter, nothing was mentioned to his owner Kaet about her kitten's unique features.

Khan, a five-year-old male White Bengal tiger, looks on inside an open-air cage at the Royev Ruchey zoo in Krasnoyarsk, Russia, October 21, 2016. (Photo by Ilya Naymushin/Reuters)

“Bazooka”, a one year old stray cat, is treated at the SPCA (Society for Prevention of Cruelty to Animals) clinic in Tel Aviv, Israel, 06 January 2016. Bazooka arrived at the clinic in critical condition after he went through severe abuse with bruises all over his body and painted with pink oxidation. The Israeli street cat population is estimated to be about two million. Without enough financial support from the state, animal rights organizations find it difficult to keep the up with the pace when it comes to spaying and neutering feral cats, causing the population to grow. (Photo by Abir Sultan/EPA)