>>165817Mules can handle rougher terrain than you'd give them credit for. Donkeys, not so much. Donkeys do have generally better dispositions than mules, though. A jackass might fit the bill for you, too, but they're up there with horses for size.
OTOH, goats are actually fairly easygoing. They're roughly as smart as dogs, cheap to get, and easily trained. We raised them for food and milk when I was a child. I'd teach them tricks just to mess with people. Get a nanny with horns, not a billy. Billy goats stink, smell their own piss, and masturbate constantly. It'd be like having your own little slice of /b/ in your yard.