10 - The Pharao = pareidolia
9 - Martian Obama = pareidolia
The colour image is made with three different photos,
here's
one of them.
If you click the "Back to Panoramic Camera Sol 620" you can see the others.
Has they also took a photo with the right camera we can get a 3D idea of what it really looks like through an animated GIF.
8 - The Mermaid = pareidolia
You can see one of the original photos
here.
7 - The Mars hieroglyphs = pareidolia + wishful thinking
The original photo is
this one.
6 - The Martian stone hut - wishful thinking (and a trick of perspective)
It's only one rock, 32 centimetres wide (according to AlgorimancerPG), not a pile of rocks.
Here's the original photo.
5 - The Martian stoneface = pareidolia + wishful thinking
Original.
4 - Dinosaur fossil = pareidolia
Original (one of the images that show it).
3 - The Celtic Cross = wishful thinking
Like
EdwardDrake said, it's a mark left by the rover.
Original.
2 - The fallen statue = pareidolia
Original photo.
1 - The Martian totem head = mostly fake
In the original image there's no teeth, and much less a lower row of teeth.
The
original photo (the source of
Zarniwoop's image, shows it. Someone decided to get creative with the JPEG artefacts.