Dismal(2009)

Dana is failing Biology. To pass she must attend an extra credit assignment with several classmates that will lead them into a remote region of the Great Dismal Swamp, a place teeming with life... and death. While the group keeps one eye out for hungry bear, deadly snakes and lurking gators, they are unaware of the real danger. For the top of the food chain lives in a dingy cabin not too far from their campsite, and he has an appetite for human flesh