J.J. Jarrett is a character in Friday the 13th Part VIII: Jason Takes Manhattan, portrayed by Saffron Henderson.
J. J. is first seen aboard the SS Lazarus, playing her guitar while being filmed by her friend, aspiring film school student, Wayne Webber. After giving him some advice about women, she heads down into the lower decks of the ship in order to take advantage of the superior guitar acoustics the cavernous interior will offer.
As J.J. loses herself in a jam session, she fails to notice Jason Voorhees stalking her until the last minute. Upon seeing him, she panics and runs deeper into the bowels of the ship. After running down a flight of steps, she suddenly stops and lets out a blood-curdling scream, just as Jason, who has gotten in front of her and is wielding her guitar, swings the heavy instrument at her head, smashing her skull.
Her body is shown later when Wayne literally falls over her while fleeing from Jason.