Never heard of Scots being called Jocks before, but I thought Limeys were the Brits in general, not just the English.
I'd personally be highly annoyed if you referred to the Scots as sheepshaggers. That's what you're supposed to be calling the Welsh.
Oh, they're far too drunk to be able to screw anything, but I suppose if they had a choice it'd have to be one of today's modern super animals, like the flying squirrel, or the electric eel.