A herpetologist is someone who specializes in the study of reptiles and amphibians. If it slithers around on its belly, a herpetologist will know what it is.
The word herpetologist comes from the Greek root herpeton meaning "creeping animal." When a herpetologist goes out searching for reptiles and amphibians, he is herping, or peeking under rocks and in the mud, hoping to find a slithery creature lingering there. What will he find? Turtles, snakes, alligators, salamanders, etc. These reptiles and amphibians are a herpetologist's forte.