The Tarnhelm is a magic helmet in Richard Wagner's Der Ring des Nibelungen (written 1848–1874; first perf. 1876). It was crafted by Mime at the demand of his brother Alberich. It is used as a cloak of invisibility by Alberich in Das Rheingold. It also allows one to change one's form:

Finally, it allows one to travel long distances instantly, as Siegfried does in Götterdämmerung, Act II. The stage directions in Das Rheingold and Siegfried describe it as a golden chain-mail helmet which covers the wearer's face.

Nacht und Nebel ("Night and Fog") was a directive of Adolf Hitler on 7 December 1941 that was originally intended to remove all political activists and resistance "helpers"; "anyone endangering German security" throughout Nazi Germany's occupied territories. The name was a direct reference to a magic spell involving the "Tarnhelm" ("stealth helmet") from Wagner's Rheingold.