Noldo-mask

Some Noldorin warriors wore helmets with visors bearing an eagle’s beak, most notably the guards of the Gate of Writhen Iron in gondolin.

The design was probably inspired by the dwarven masks and the great eagles of Cirith Thoronath.

speculations
Tolkien´s description of the Noldorin Masks maybe were inspired by historical helmets, especially the hounskull but perhaps also by the Jousting helm and armet.