The Hannya (般若) mask is a mask used in Noh theater. It possesses two sharp bull-like horns, metallic eyes, and a leering mouth split from ear to ear. The mask expresses the fury of a vengeful woman turned demon through pain and rage.
Hannya mask is used in Japanese Noh theater, representing a jealous woman with a demon-like look. "Hannya" is a Japanese Buddhist term. The word means wisdom, the ability to know truth. The artist would need a great deal of the the "wisdom". The Heart Sutra, known in Japanese as Hannya Shingyo, Japanese Buddhist sutra, contains many gems of wisdom, things that we tend to forget..