Please help me, I am looking for the title of and 80's movie where an alien is in the house and it is in the pool and it kills the parents and neighbors and the boy and his grandfather has to stop it, but a really memorable scene is in the bedroom when the boy opens the door the alien pops the heads out from underneath the sheets and they can talk. That is all I can remember I would appreciate anyone who could help thanks.

Try the old 80's movie called TerrorVision. It has aliens, a teen kid, neighbors, parents and a Grandfather who helps the kid kill the aliens. But since I never saw it, nor can I find a full description, I don't know if there are any talking severed heads in it.