Ok, this was a TriStar and Sony pictures production/distribution. 80s – early 90s. Action takes place on Earth (mostly) and on the spaceship near it. Some rogue creature got onto the alien spaceship and killed all crew. One member managed to escape to Earth. Took human form (woman). The rogue creature follows her to eliminate. She gets in touch with a local cop (man) after one of the creature’s attempts on her. She tells him what’s is going on and they commence a hunt on the creature. They call the creature a Unicorn (at least in the translation). They understand that firearms not effective and they need alien weapons. Somehow they go to the ship to pick it up – it is like a rifle but with a thick shiny cylindrical barrel. Shoots with some laser/energy pulses displayed as short rays of light.
In the meantime that creature occasionally kills people. When the attack happens is starts from the underground as a small hump that moves towards the victim. The victim gets sucked halfway underground and screams.
At some point an encounter, a stand off happens and the creature escapes to the spaceship, probably being wounded. The alien woman says they need to follow it and kill. They follow to the spaceship. The ship or a rescue capsule is full of dead aliens. They all have human form. They are dead and float in the ship. Our heroes move across the ship and this creature possesses dead alien bodies on their way – a black claw protrudes from the body while it attacks them. The cop shoots at possessed bodies. Then there is a final standoff. I think the creature is some shiny black thing, but I was too scary to watch it.
I would greatly appreciate if you can help identify it.