A stone placed on a row of stones so that it reminds the viewer of a high domed shell of a box turtle with a nuchal notch and directly below that, on a flat platform of another stone, a stone placed to represent a head - and below that perhaps a spot to rest a clam shell of tobacco mixture...
(Looking for smaller cobble sized turtles, I failed to notice the boulder turtle with a protruding nuchal notch in its shell, the protruding (but not that much) head below it:
(My "facial recognition software" hadn't quite kicked in yet...)
Two stones of the same type and color, placed just so - was the mouth-like smile already there or did some human do something to make it look "more so?"
The "Open Mouth" idea (next to a foreleg?):
Slithering along farther: