It posed nicely for me. Had a bit of a belly so full of something or a baby?

Sceloporus merriami, commonly known as the canyon lizard, is a species of lizard in the family Phrynosomatidae. The species is native to the south-western United States and northern Mexico.
Dorsally, the canyon lizard is gray, tan, or reddish-brown, matching the rocks on which it lives.