LOLcat

or lol·cat

[ lol-kat ]
/ ˈlɒlˌkæt /

noun

(on the Internet) an image of a cat accompanied by misspelled or grammatically incorrect text that humorously represents the cat's imagined thoughts or comments on what the image is depicting.
an Internet fad or meme typified by such an image.
the innovative spellings or language of LOLcat: the rules of LOLcat.

Origin of LOLcat

First recorded in 2005–10; LOL + cat

historical usage of LOLcat

See Internet.