Surprise ! Usually when walking around near swamps people check where they step. Great idea, but that should not be the only thing you watch for.
Not one, but two !
These look like Ribbon Snakes. The tree might be where the female is placing her eggs.
The good news here is these snakes are harmless, except to the things we like them to eat.
This tree is hanging over a path, near a marsh, that many visitors to the Charleston area walk under. None know what looks down as they walk and talk among themselves.