Nehebu-Kau was a snake god, "He who harnesses the spirits", whose invincibility is a source of protection both in Egypt and in the Underworld.
In the Pyramid Texts Nehebu-Kau is called "son of Selkis), the scorpion goddess, emphasizing his role in later spells of restoring the health of victims of venomous bites. Protective of royalty, Nehebu-Kau receives the monarch in the Afterlife and provides a meal. A Middle Kingdom spell identifies the deceased with this snake god who is not subject to any magic, nor vulnerable to fire and water. One source of his power lies in the magical force of the number "seven" in the seven cobras which he swallowed. In a spell concerning the welfare of his heart in the Afterlife, the deceased requests other deities to give him a good recommendation to Nehebu-Kau. There is a hint in the Old Kingdom that Nehebu-Kau's power needs to be controlled by the sun god Atum pressing a fingernail on the snake's spine.