Me Gusta is a black and white line drawing depicting an out of proportion head with a goggle-eyed look. The character in the cartoon responds to anything with the phrase "Me Gusta", which is Spanish for "I like it", which is a loose translation of the more accurate term "It pleases me".
Many memes are a response to various statements, events, and happenings as a one-liner reply indicating the finality of the argument. Me Gusta is no exception.
The humor is derived from the character responding "Me Gusta" to things that normal people would not like, or that would be considered out of the realm of anything likable.
Me Gusta is also part of a four panel editable comic with the head as the last panel.