The three pictured here are in order of increasing size and age. As they get older, the ridges on their head and face become more and more defined and more and more black.
And yes, that biggest one decided to empty its bladder just before I got a photo.
- Incilius mazatlanensis account on AmphibiaWeb
- Incilius mazatlanensis account on Tucson Herpetological Society site
- Rorabaugh, J.C., Lemos-Espinal, J.A. 2016. A Field Guide to the Amphibians and Reptiles of Sonora, Mexico