For sticklers for history...the Totenkopf did not originate with the Nazis.
Totenkopf (German: [ˈtoːtn̩ˌkɔpf], lit. ‘dead person’s head’) is a German compound word for death’s head. The word is often used to denote a figurative, graphic or sculptural symbol, common in Western culture, consisting of the representation of a human skull – usually frontal, more rarely in profile with or without the mandible. In English, the term is associated with Nazi Germany, where the skull insignia was used as a uniform emblem of the SS.
https://en.wikipedia.org/wiki/Totenkopf