The sign of the Elder gods – which represents man.
"The Sign of the Elder Gods (the Elder Sign) is a magical tool used by both witches and magicians to keep mischievous forces at bay. ⭐️
In the distant past, the Elder Sign represented man — the five points being his head, two arms, and two legs. The sign of man.
Inverted it became the symbol of Shub-Niggurath, the Black Goat of a Thousand Young = the five points being two horns, two ears, and the beard. 🐐
Gradually, the true meaning of the Elder Sign vanished into the mists of time to be “replaced” with the Pentagram, and Baphomet — an idol with the head and feet of a goat, the breasts of a woman, and the wings of an angel.
The Necronomicon unlocks the gates to another dimension, to another race of beings.
It tells of an ancient time when an earlier race superior to man inhabited the Earth and how, with certain rites and incantations, this race, the Old Ones, can be brought back.
The Necronomicon also relates how Cthulhu was taken by the Elder Gods, whom He had defied, and placed within a stone tower that rose above the sunken ruins of R’lyeh in the nethermost depths of the eternal sea, and sealed within by the Elder Sign. ⭐️
The Old Ones once walked where man now walks, but were cast out by the Elder Gods, and sealed away outside of time and space."
TLDR: If you summon the Old Ones, the Elder God's, the primal forces will not be amused is the theme here...