Creatures with Black Fur Become Fur Ball!

by adam
(spain)

I can't remember the title or any of the actor's names in a movie I saw years ago, but I am looking for some help with the title. I will try to describe what I remember...

I saw this movie on TV around the early 90's. I remember that the monsters at beginning of the movie were small and attack humans and after a while they connect to each other to become a giant fur ball.

Can anyone help me with the title?