From Fear to Eternity Charmed : Season 1 Episode 13

The sisters' mother warns them about a demon from the underworld who comes around every 1300 years on Friday the 13th to literally scare witches to death and feed on their fear. Meanwhile, Phoebe has misgivings about her expected duties at her new job and Piper is frustrated by her superstition about relationships started on Friday the 13th.