Varahi, Avatar of Vishnu depicted as Female Version of Varaha, the Boar

One of the Sapta Matrikas (Seven Mothers), Varahi is depicted with the head of a sow, She is the shakti (feminine energy, or sometimes, consort), or female version, of Varaha, the boar Avatar of Vishnu. She is usually worshipped at night, and according to secretive Vamamarga Tantric practices. (From the Devi Mahatmya of the Markandeya Purana.)