Some dragon heads done for practice and client examples. Trying to incorporate more varied scale patterns based on strange and uniquely adorned reptiles. Lots of Thorny Devil inspired spikes in these guys. I also found lots of great reference over at The Lazy Lizard's Tales blog, here: http://lazy-lizard-tales.blogspot.com/
One thing I was definitely reminded of when looking for eccentric looking lizards was that truth is indeed stranger than fiction. I've found reptiles more fantastical looking than many dragon designs I've seen. For example, the previously stated Thorny Devil, the Sailfin Dragon Lizard, Marine Iguana, Frilled Necked Lizard, and the Phrynocephalus mystaceus.
This guy was inspired by rhinoceros iguanas and a multi-horned jacob ram.