Red Christmas

A family gathers together to celebrate Christmas. Amidst the celebrations, a mysterious, cloaked stranger, "Cletus" arrives at the house and is taken in as a guest. He reads a letter he wrote to the family and after he discusses the topic of abortion, he is forced to leave the home and is told that if he decided to return, he would be killed.
It is eventually revealed that 20 years ago, the matriarch of the family, Diane (Dee Wallace), travelled north to have an abortion. During the procedure, a religious fanatic bombed the clinic and took Diane's planned to be aborted child which is revealed to be Cletus. Cletus has now returned to the family home to violently exact revenge on her entire family.
During the night, Cletus kills Hope with an ax, and proceeds to strangle Joe in a car. Cletus smashes Scott's head. A police officer eventually arrives after being called earlier, unfortunately Cletus murders him almost immediately. Later on, Cletus forces Peter's head into a blender. Diane accidentally shoots Jerry. Ginny gives birth to the baby. Cletus stabs Suzy with an umbrella. Cletus stabs Ginny in the back and gently rests her newborn baby onto a table. Diane stabs Cletus with an anchor chained around her neck, then leaps out the window of the second-floor room, hanging herself and ripping out Cletus' insides, leaving Ginny's newborn baby as the sole survivor of the night.