Scarecrow

Scarecrows were man-like figures intended to deter crows from eating crops.

Scarecrow disguises
briefly dressed himself up as one in order to spy on the Sixth Doctor. (TV: The Mark of the Rani)

After his defeat by the Tenth Doctor, Son of Mine was made into an immortal, living scarecrow. (TV: The Family of Blood)

Animated scarecrows
The Time Lords made animated scarecrows. (COMIC: The Night Walkers) The Family of Blood also made animated scarecrows. (TV: Human Nature / The Family of Blood)

Behind the scenes

 * The script to the un-produced film Doctor Who Meets Scratchman also featured walking scarecrows.