Monster in a house which absorbs people and then looks like them

Question

I saw this movie at least 10-15 years ago on TV.

As far as I can remember there is a monster in a house, I think a party was going on. Well the monster can absorb and look like people it absorbs. Some kids and teens are the main characters trying to stop the monster. At one point they think it is friendly and they are feeding it hot dogs but the thing got spooked and decided to absorb the teen guy who was if I remember dressed like a punk guitarist.

At the end of the movie it turns out the monster was a pet from a different planet and when the alien came to retrieve it and help, the kids cracked its space helmet thinking it was a bad alien and before the scene cuts they are all getting sucked in by the pet monster. It ends with the monster getting in a cab or car, and I think the driver makes some joke about a Halloween party gotten out of hand, not knowing the thing in his car is the monster.

Hope this give some clues because ever since I saw it as a kid I always wanted to watch it again for fun.

P.S. I think the monster looked like Jabba the Hutt ish when it was failing at copying an entire human's looks.

Answer 1

As already confirmed by the OP in comments, this is the 1986 horror comedy TerrorVision. From Wikipedia (emphasis mine):

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.

_{Answer inspired by Walt's answer from another site.}