Single Horn Serpent Being From Jerry Zani (RI)

Jerry Zani contributes many fine photos here:

https://www.facebook.com/groups/4585999861

Quite possibly, this segment of a larger row of stones, may be stacked to resemble a single horned serpent being found in other Indigenous art forms such as this petroglyph:

A Single Horned Snake in a Pictograph:

See also: 

https://wakinguponturtleisland.blogspot.com/2016/02/adding-single-or-one-horned-horned.html

https://rockpiles.blogspot.com/2016/12/horned-serpent-washington-ct.html