Pictured is one of my favorite species of lizards to "hide" in a desert painting.
It's a zebra-tailed lizard (Callisaurus draconoides), a species that is fairly common throughout the Southwestern deserts. I've seen them a number of times and have even been lucky enough to take some pictures of them before they disappear within the blink of an eye.
This particular individual, however, is a sculpture. It looks real, but it's made of polymer clay. (Polymer clay can be "fired" in a standard household oven, unlike dirt-style clay which must be fired in a high-temperature kiln). He (or she?) was made by an artist friend who for years has been making lizards, snakes, frogs and turtles. Lately she's been adding more colorful/decorative critters to her production.
The artist's name is Sandra Lee, and you can see what she's been up to here: http://picasaweb.google.com/SandraLeeandNat
I have quite a collection of her sculptures, most of which have appeared in numerous paintings. These, plus with the help of the photos I've taken of these desert reptiles, have aided me greatly in adding just a little life to my desert artwork.