Stalking-horse
.A mask to conceal some design; a person put forward to mislead; a sham. Fowlers used to conceal themselves behind horses, and went on stalking step by step till they got within shot of the game.
N.B. To stalk is to walk with strides, from the Anglo-Saxon stœlcan.
“He uses his folly like a stalking-horse, and under the presentation of that he shoots his wit.”—Shakespeare: As You Like It, v 4.