Hel is a giantess and goddess who rules over the identically-named Hel, the underworld where many of the dead dwell. Hel is generally presented as being rather greedy, harsh, and cruel, or at least indifferent to the concerns of both the living and the dead.
Hel has no organized worship. Her few living worshipers keep to themselves, plotting against everyone they feel has wronged them.
Hel teaches no particular dogma to the living, focusing instead on her dead minions. She does have a cult devoted to her, however. Its members feel that society unjustly imprisoned, exiled, or ignored them, and often seek revenge for real or imagined slights.
She appears as a gaunt woman whose body is fair and lovely on one side, but dead and rotting on the other. Despite her hideous appearance, she is the least monstrous of Loki's three children from this union (the other two are Fenrir the wolf and Jormungandr the world serpent).
Hel is the daughter of Loki and the giantess Angrboda, and therefore the sister of the wolf Fenris and the world serpent, Jormungand. This makes her part of a highly dangerous and disreputable family.