I remember my father using the phrase "thick as a bull's foot", which is more poetic than ridiculous. Is that a Welsh regionalism?

Another one, which I am pretty sure is peculiar to the Canadian Forces (and a bit out of date now - last year I heard a middle aged officer reminiscing about it) is "ya frggin' jabony". That too is probably poetic. My best source on such matters (Charmion) says it is a contraction of "Jesus bonehead".