Origin: Negligent camp counselors let poor little Jason drown as boy. Somehow he survived and now stalks anyone who visits Camp Crystal Lake. He also takes occasional detours to Manhattan and space to kill people there.
Favorite weapon: He likes to keep a machete handy, but he'll use whatever's around.
Mask: A hockey mask. Just a plain old hockey mask.
Should you be scared? Oh yes. The guy is a killing machine. If he gets you in his sights, you're toast.
Franchise: "A Nightmare on Elm Street"
Origin: Child-ravager Krueger got burned to death by a lynch mob. Now his spirit kills children where their parents can't protect them - in their dreams.
Favorite weapon: A modified glove with knives for fingers (he builds these during daylight hours killing time until he can kill kids).
Mask: He doesn't need one. No mask could possibly be as scary as Krueger's hideously burned face.
Should you be scared? If you're alert enough to be scared, then you're probably awake and have nothing to fear. Kind of an unusual catch there.
Origin: No backstory here. The killer has a different secret identity in each film. What they all have in common is that they like to call up their victims and torment them over the phone them before attacking them.
Favorite weapon: Mostly knives, occasionally garage doors.
Mask: A generic department store mask that allows them to blend in with other Halloween buffs.
Should you be scared? Ghostface is always just people under masks. They are surprisingly easy to fight off, so long as they don't get the jump on you.
Origin: Long-suffering cancer patient John is bitter at those who take life for granted. He puts such people in dangerous "games" to teach them valuable lessons. Of course, most victims don't survive long enough to get a new lease on life.
Favorite weapon: Jigsaw is a technical genius and comes up with various complex devices to maim people.
Mask: Jigsaw and his accomplices often wear rotting pig masks that symbolize his disgust with humanity.
Should you be scared? Of him, no. His sickness has more or less left him an invalid. But if you get knocked out, wake up in a locked room, and hear a voice saying "I want to play a game," then yes, you should definitely be scared.