You're walking in the woods, there's no one around and your phone is dead, and out of the corner of your eye, you spot him.

He's following you, about thirty feet back. He gets down on all fours and breaks into a sprint, he's gaining on you.

You're looking for your car but you're all turned around, he's almost upon you now and you can see there's blood on his face, my God there's blood everywhere!

Running for your life, he's brandishing a knife, lurking in the shadows. Living in the woods, killing for sport, eating all the bodies...

Werewolf.