Hehehe, get it? Knot.
I found some "rustic" 4/4 hickory that was full of knots, worm holes and funky grain for sale for just over a buck a board foot. So I bought a 1x12-10'. It had one really open and ugly knot in it that was surrounded by worm holes, and I thought I'd see if I had enough CA glue to keep it together and turn it into a turkey call. This is by far the most difficult call I've made. Up until the last minute turning it, I fully expected it to blow up, but it never did. I'd cut a little, glue a little, then cut a little more, and so on. I abandoned my usual center 1/2" hole because nature provided this one. Hard to tell from the pic, the knot has three legs that are wide open so you can easily see all the way through. The finish is tru oil.
I'm regretting it because I hate the look now that it is glued together, but I used a glass soundboard and a glass surface. In hindsight I should've gone with glass over aluminum or glass over slate. Oh well, it isn't one I'm selling anyway. Might have the engraver scratch my name in the glass next time I'm there. It does sound good though!