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)

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 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)

Manhattan's most fashionable felines dressed their best to help Matilda, the famous Algonquin Hotel cat, celebrate her 15th birthday on Aug. 11, 2010. The party was held in the hotel's lobby and centered around a good ol' fashioned cat fashion show. (Photo by Katie Sokoler/Gothamist.com)