Como já foi confirmado pelo OP nos comentários, esta é a comédia de terror de 1986 TerrorVision . De Wikipedia (ênfase minha):
On an alien planet named Pluton, an alien garbage disposal converts a monstrous mutant called a Hungry Beast into energy and beams it into space. Meanwhile, on Earth, the Putterman family is getting satellite television, courtesy of a temperamental DIY satellite antenna. The reception is poor at first, but suddenly strengthens when a bolt of the alien energy hits the dish.
Sherman Putterman and his ex-military, survivalist grandfather set out to enjoy a night of horror films hosted by the buxom Medusa. Meanwhile Sherman's parents go out to meet some swingers and his sister Suzy goes out with her rocker boyfriend O.D. Sherman and his grandfather eventually fall asleep, but are awakened when the Hungry Beast materializes out of the TV and eats the grandfather. Sherman's parents later arrive along with swingers Cherry and Spiro. Despite Sherman's plea, his mother locks him in the fallout shelter so he will not ruin their evening.
[...] Sherman's sister doesn't believe his story about a monster, and when they check their parents' room, they find imitations of them, their grandfather and the swingers. Soon after though, they encounter the Beast in another room. It chases after them, but relents at the sight of O.D.'s heavy metal paraphernalia, which he finds appealing due to its resemblance of his caretaker's gloves. They then discover that they can subdue the Beast with food and television, and teach it a few words such as "TV", "music" and their names. They consider using the Beast for profit, and call Medusa in the hope of securing a TV appearance. She is initially dismissive, but shows interest when they promise to hold a party.
[...] The next morning, Medusa's chauffeur is woken up by a crude imitation of his employer hiding in the back seat of his car, demanding to be taken to the TV station.
Resposta inspirada por resposta de Walt de outro site.