Back in the summer of 2008, I was lucky enough to take this picture of a coast horned lizard (Phrynosoma blainvillii) that I caught at Santa Margarita Ecological Reserve in southern California. This lizard used to be found throughout much of California, but its populations are declining from habitat destruction and the spread of nonnative ants, such as the Argentine ant (i.e. the little black ants you usually find in your backyard).
The blood smeared across its face is not from an injury, but a peculiar defense that many species of horned lizards have evolved to escape predation from foxes and coyotes. If a fox grabs it, the lizard will squirt blood out of its eye! The blood puts a bad taste in the mouth of the fox, probably because it is full of nasty chemicals, such as formic acid, from all of the harvester ants (Pogonomyrmex sp.) the horned lizards eat.
Further reading about this cool behaviour: Responses of Kit Foxes (Vulpes macrotis) to Antipredator Blood-Squirting and Blood of Texas Horned Lizards (Phrynosoma cornutum)
Further reading about horned lizard biology: Horned Lizards by Eric R. Pianka and Wendy L. Hodges