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 is examined by the jury during the first day of the Super Cat Show 2014, on November 8, 2014 in Rome, Italy. The Super Cat Show 2014, which takes place on the 8th and 9th of November, involves the participation of 800 cats of different breeds from all over the world. (Photo by Giorgio Cosulich/Getty Images)

The selfie is the most popular photography trend of the internet today. It's gotten so popular, in fact, that even our beloved feline friends have started to catch on. I dare you to keep the smile off your face for this one!

Pickles the cat was once abandoned and had a hard time finding a home because of his size until he met a couple who have a heart and home big enough to take him in.

A cat yawns at Nekorobi cat cafe on January 20, 2009 in Tokyo, Japan. Cat cafes, where people can spend time with their favorite cat for about 10 US dollars an hour, are now getting more popular with people living in urban areas. The regular customers are mainly in their 20's to 30's and seaking healing by cats, or people who cannot afford to have pets full time. Some visiters come to the cat cafe three times a week. (Photo by Junko Kimura/Getty Images)

Most pet cats will become timid or defensive when outdoors, but not Millie – after being adopted by her mountain-climbing owner Craig Armstrong, Millie has become a feline hiking and mountain-climbing legend.