A lolcat is a picture of a cat with a funny caption. The caption is usually in bad English that makes fun of Internet slang. "Lolcat" is a mix of the words lol and cat. Lol is internet slang for "laughing out loud."  A different word for lolcat is cat macro because it is a type of image macro.  The first time the media talked about lolcats was when Time Magazine covered them in an article. The article said that lolcats and other things like them are becoming rare. It also said that they have a "distinct...Usenet feel to [them]." 
There are lots of different lolcat memes with more getting posted every day, like ceiling cat, monorail cat, 'i eated a butter' cat and many more.
- Dwight Silverman (2007-06-06). "Web photo phenomenon centers on felines, poor spelling". Houston Chronicle. http://www.chron.com/disp/story.mpl/business/4862013.html. Retrieved 2008-09-21.
- Randy A. Salas (2007-06-09). "Laugh at cat humor". Akron Beacon Journal, Star Tribune. "At first, they were called cat macros, but now go mostly by the name lolcats."
- Grossman, Lev (2007-07-12). "Cashing in on Cute Cats". Time Magazine. http://www.time.com/time/magazine/article/0,9171,1642897,00.html. Retrieved 2007-07-12.