Spica is the reincarnation of Angrboda, the giantess who bore three of Loki's children (the ones that were a precursor to Ragnarok). She is the mother of Fenrir, Jormungand, and Hel. In her human form, Spica is a normally mute girl with a huge appetite. In the anime she only appears briefly in the final episode, but in the manga is shown that Loki has a great affection for her. (Source: Wikipedia)