What classes do you need to take in high school to become a herpetologist?

Answer 1

You should take general college prep courses, with particular attention to the sciences, especially Biology, though this part isn't absolutely essential.

Essentially no one becomes a herpetologist straight out of high school (you could try, but good luck finding a job). You'll most likely wind up going to college and majoring in biology, which is why I mentioned "general college prep courses."

In college, you'll probably find out that 90% of what your high school biology teacher told you was either oversimplified or outright wrong, which is why the biology emphasis in high school isn't all that essential.