Knotted Serpentes by The Scarlet Letter
It is executed almost entirely in cross stitch over two threads of linen, with the outer border filled in with counted thread satin stitch.
***This chart is designed after a cruciform-shaped embroidered panel made by Mary, Queen of Scots!***
Marsha has been reproducing samplers longer than pretty much anyone. I was lucky to tour her farmstead back in the 90s, and it continues to be a memorable day. Her reproduction charts are thorough, and come with stitch diagrams.