Leeches R

The Lakecrest College swim team is determined to win at all costs, even if it means taking steroids. But winning comes at a horrifying cost when harmless leeches in the campus lake, quietly feeding on the steroid-rich blood of the team's swimmers, mutate into giant parasites with a vicious streak. No one is safe as these ferocious creatures brutally stalk the students and staff of the rural college and literally bleed them dry!

Common-type aquatic leeches grow to large size after feeding on steroid-laced blood of a number of college endurance swimmers, and then the nasty creatures lay siege to the entire campus for more. It's slime meets speedos in this Syfy channel hit!