Some people hunt animals for sport; Ramsay hunts women. He allows Tansy, a servant of House Bolton, to attempt an escape through the woods, before he and Myranda - a lover of Ramsay - give chase along with his hounds, the Bastards Girls. Ramsay taunts Tansy during the chase, letting her know that if she escapes she wins. Myranda eventually hits her with an arrow to the leg, and as she pleads for her life, before Ramsay sets his dogs on her. Joffrey does of course have his own dog that he can set on people, but even The Hound would probably draw the line at such pointless brutality, and while it is the sort of game you can imagine Joffrey liking, it's not so easy to imagine him actually doing the dirty work himself, nor being clever enough to come up with such games.