Simhamukha (Tibetan Seng-gdong-ma) is a wrathful dancing dark-blue figure similar to Vajravarahi in appearance and ornaments, holding a curved knife in her right hand and a skullcup in her left, except that she also has the face of a lion - hence her name in Tibetan and Sanskrit (meaning "lion-face").
Her practice was founded by a woman, Jetsun[ma] Lochen; Simhamukha is regarded as a dakini form of Padmasambhava, the (male) founder of Buddhism in Tibet (see also Mandarava and Yeshe Tsogyal).