Without Warning (1980)
Without Warning, which is also known as It Came... Without Warning and Alien Shock (German title), is a 1980 science fiction horror film starring Jack Palance, Martin Landau, Tarah Nutter, and Kevin Peter Hall (Predator), directed by Greydon Clark. Special effects designer Greg Cannom, who was later involved in major studio productions such as Jurassic Park, Hook and Titanic, created the memorable aliens for this low-budget film.
More at Wikipedia.