There is a teacher I really dislike and feel like punching him on the back of his head

Your work is not parallel to his. You’ll stay influential in those kids’ life, and the good you’ve done will resonate with them forever

If you've seen the movie Amelie, think of how she gets back at the awful people by playing wicked little tricks on them, this is how that jerk should be dealt with a kind of elaborate scheme that would reduce him to an emotional wreck who'd from then on make better choices, and a permanent limp, like the angel wrestler Jacob.

Sounds like a real jerk...why are there so many?

Do your best not to punch him in class or anyplace that you're easily identifiable...

is there any entity to lodge a complaint with, where that would have any actual impact?

you can at least convey your thoughts to him (if you haven't already), I'm sure you could make quite an impression on him that he won't forget even if you can't punch him