Who is the killer in "Friday the 13th" (1980)?

Mrs. Voorhees was the original Crystal Lake killer, running around in a cable knit sweater murdering horny teenagers because they let her precious Jason drown. Jason didn't show up with his machete and hockey mask until the sequel, he was too busy being "dead" in the lake while his mom sought revenge. Who's scarier, an angry mom in comfortable shoes or the undead guy in a mask? I'll leave that up to you.