It's a children's plastic doll which come to life and is murderous.
Meaning it is carrying a knife, and maybe a chainsaw, to murder an entire family (maybe wrong here).
I think somewhere in the movie we get to see the factory in which those dolls are manufactured and where this doll chases the family. And since there are thousands of these dolls stacked up all over the place they find it difficult to figure out the one which had come to life and was chasing them.
The doll had scant hair blonde hair. I guess it had blue eyes.
Which movie could this be from?