I just added the below image that contains two rather angular-looking serpents to the blog post Serpent & Ophicleide: History and Images. For another angular serpent, see c. 1630 of the same post. For a modern version of the instrument, called a “squarpent” by the maker, see here.

1637—Italy: A frontispiece for a collection of instrumental works by Girolamo Frescobaldi shows two serpents among the decorative clusters of instruments (see middle-left and middle-right, below; public domain) (Emilia Romagna 67).