For 75 years the Italian jewelry house Bulgari has created and recreated the image of a snake in its jewelry and watches — and more recently, in its accessories, with the reptile’s distinctive ovoid head appearing on everything from handbags to eyeglasses.

The serpent has rewarded that devotion by becoming the house’s muse and best seller. “Serpenti is our leading line,” Jean-Christophe Babin, the house’s chief executive since 2013, said in a recent interview in Geneva. “Sales have gone up 30 times in the past 10 years.”