The Scarecrows were the terrifying henchmen of a group of aliens known as the Family of Blood. The Family had the ability to not only inhabit the bodies of what they perceived as lesser species, but also to animate inanimate objects.

The abundance of scarecrows in a quiet English village provided the necessary material for the family to raise an obedient army.

Used mainly for extra brute force in the Family's battle to capture the Doctor, they literally were used as cannon fodder to attack the military academy in which the Doctor was taking refuge.