Hild (ヒルド Hirudo) is an Ah! My goddess character. She's the ruler of demons, holding the title of Daimakaicho (lit. Great Demon Leader) and is the opposite of Tyr, the leader of Heavens (also referred to as Almighty for most of the series). Still, she's Urd's mother, whom she loves, even though the latter tries to keep a distance, fearing that getting too close to her would make her demon side take over.
Despite being Tyr's first wife (or lover), Hild seems to get along with Belldandy and Skuld, who remind her of their father, even though at some point in the series she antagonized them for a while, using a 1/1000th avatar of hers that she left behind after her visit to the mortal realm.
It should be noted though that she probably held back considerably, since she's one of the most powerful entities in Ah! My goddess, with the closest match being Tyr himself, or Ansuz (the mother of Belldandy and Skuld). Actually, her relationship with Ansuz strongly resembles the antagonistic attitude between Urd and Mara, even though their antics seem much more extreme and destructive.
She's voiced by Gara Takashima.