What is this mystical beast, an ewe with a crooked horn? Well, it's a still. An illicit one, of course.
And now it's easier than ever to envision, since a reenactor's sutler, Goose Bay Workshops, has begun producing a reproduction of an 18th century still:
The picture shows the still (right) and the condenser worm (left). When in use, the still would sit on a 3- or 4-legged trivet over a fire, which might look like this:
With the trivet as the legs, the handle as the head, and the vat as the body, you have your ewe; and the crookit' horn is the condensing tube from which the magical "water of life" emerges.
I'll drink to that!