Some guy was looking at photos taken by one of our crawlers on the surface of Mars and decided that he was seeing a Martian. A lizard-like creature with 4 legs and a tail.
Here it is. Look right in the center of the image.
Now, if this is indeed the first photograph of a Martian, then we have two profound discoveries made here. One is that lizards exhibit convergent evolution having evolved to the same life form on separate planets, and the second is that lizards on Mars exhibit protective coloration or can change their skin color to match their surroundings, like chameleons and geckos do here on Earth, because the skin color of this Martian lizard is identical with that of the surrounding rocks
Either that, or it's a rock.