Drowned Moon

On a pitch black night when the moon wasn't watching, a piece of her was stolen and smuggled across the sea. But mid journey, the moon found out, pulled at the waves and sunk the thieves and her child to the bottom of the ocean. Stranded from her mother, the small piece of the moon was consumed by darkness at the bottom of the ocean where it corrupts the mind of an octopus deep in a lair where merfolk fear.