Stalk"ing-horse (?), n.
1.
A horse, or a figure resembling a horse, behind which a hunter conceals himself from the game he is aiming to kill.
2.
Fig.: Something used to cover up a secret project; a mask; a pretense.
Hypocrisy is the devil's stalking-horse under an affectation of simplicity and religion.
L'Estrange.
How much more abominable is it to make of him [Christ] and religion a stalking-horse, to get and enjoy the world!
Bunyan.
© Webster 1913.