You must remember that the Mars Rover took that shot. Considering how small it is, and the distance that image was taken at, that thing is not very tall. It may only be as tall as your ankle. Little men from Mars is a saying, but this is ridiculous. Interestingly, the photos were released originally as Bigfoot Found on Mars.
hmmm... maybe if it was in the shape of a man in a space suit..... lol thats a rock or shadow or something Maybe its BIGFOOT!!! :O