An aegis is a protective element that combines a broad collar with the head of a deity. Most represent the head of a cat- or lioness-headed goddess (Bastet, Sekhmet, Tefnut, etc.) or the head of Mut, Hathor and Isis. Male deities are much rarer and include mainly Bes and Amun-Re. Such amulets were either pendants or ring bezels of New Kingdom date onwards1
Silver Sekhmet with a wedjat H 2.9, W 1.8 Undated © The Trustees of the British Museum #EA29500
Gold with encrustations of an aegis of Bastet or Sekhmet H 2.5, W 2.0, D. 1.0 Third Intermediate Period MET #2016.493
Blue glazed aegis bezel ring of Sekhmet? H 2.4, W 1.7, T 0.5 Late Period Private collection DA
Reference
1Andrews C. Amulets of Ancient Egypt, 1994, p. 41, Figs. 45b,c