The Horned Helmet was the helmet Loki wore during his time as Asgardian royalty and his crusades. Its horns are an Asgardian symbol for the sorcery he wields.
To be added
Loki wore his helmet outside in Germany when he used his Scepter and began talk down to civilians, only for Tony Stark to defeat him.
Return to Asgard
To be added.