A lot of people saying that this rodent, lizard, guinea pig or squirrel was part of a NASA experiment to test how long it would live on the surface of Mars. It’s certainly plausible that NASA would engage in such experiments
NASA explains that despite its appearance, the infamous Mars rat is most likely a rock.
NASA: “Clearly, it results from a lot of things like wind erosion and mechanical abrasion and breakdown chemical weathering of the rocks, as to why they get these weird shapes.”
The psychological phenomenon “pareidolia” is the tendency to find faces, or facial features in inanimate objects (often an image or sound). Common examples include seeing images of animals or faces in clouds. Humans sometimes see things where they are not.
"Pareidolia" effect or another Mars rat?
Curiosity photograph (SOL 0310) shows another Mars Rat.
Date: June 20, 2013
Time: 13:55:06 UTC
Is it a Rock or is it a Rat?
Original Image (Link to original image)
The same photograph shows a fossilized alien skull.
Please decide for yourself.