Chthonic deities in mythology represent the spirits of the underworld and the earth, often associated with the dead, fertility, and the cycle of life and death. They hold significant roles in various mythologies, reflecting the beliefs surrounding life after death and the mysteries of existence. These deities are often linked to agricultural fertility, as they control the decay and regeneration of plants. Their worship emphasizes the importance of honoring ancestors and the earth's cycles, underscoring themes of life, death, and rebirth that are prevalent in many cultural narratives.