Nature of the Beast is a 2007 American horror romantic comedy television film starring Autumn Reeser and Eddie Kaye Thomas.
A werewolf movie, it premiered on ABC Family in 2007 and ran several times during its "13 Nights of Halloween" feature.
As the full moon rises, Rich ruses back to his room to take the medicine, but finds it gone; he locks himself in a bathroom and transforms into a werewolf.
Julia eventually discovers the truth, and after an argument (about her idiot cousins taking the medicine he needs to control the change), they reconcile their differences.
Rich explains that when he was in college, a werewolf bit him on the rear when he and his buddies were climbing over a gate to escape.