'The Slumber Party Massacre' Star Michael Villella Dead at 84

Michael Villella, the star who famously played Russ Thorn in the 1982 horror film "The Slumber Party Massacre" has died ... TMZ has confirmed.

Michael's daughter, Chloe, tells TMZ ... he passed away on Saturday afternoon due to multiple organ failure after spending over a month in the hospital.

Chloe Villella posted a tribute on Facebook Saturday with the caption ... "May you rest in peace daddy ♥️💋."

While best known for his work as Russ Thorn, Michael also starred in "Love Letters," "Wild Orchid II: Two Shades of Blue" and "Gotham."

Michael is survived by his daughter and his ex-wife.

He was 84.

RIP