Alexander Dyce, A General Glossary to Shakespeare's Works

stalking-horse either a real horse or an artificial one, under cover of which the fowler approached towards and shot at his game: “He uses his folly like a stalking-horse,” AS YOU LIKE IT, v. 4. 100. ( “It is particularly described in the Gentleman's Recreation: ‘But sometime it so happeneth that the fowl are so shie, there is no getting to shoot at them without a stalking-horse, which must be some old jade trained up for that purpose, who will, gently, and as you will have him, walk up and down in the water, which way you please, flodding [qy ?] and eating on the grass that grows therein.’ Fowling, p. 16, 8vo. He [sic] then directs how to shoot between the horse's neck and the water, as more secure and less perceivable than shooting under his belly. But ‘To supply the want of a stalkinghorse, which will take up a great deal of time to instruct and make fit for this exercise, you may make one of any pieces of old canvas, which you must shape into the form of an horse, with the head bending downwards, as if he grazed, etc.’ Ibid. He directs also to make it light and portable, and to colour it like a horse.” Nares's Gloss. in v. )