"Let me lay eggs. Just like that day, let me lay eggs."
Said by a man wearing a costume reminiscent of the Innsmouth-style fishmen.
Deep Ones are humanoid beings that live deep in the ocean. They possess both fish and human-like characteristics. Their skin is scaly, often described as being green or gray, and they have gilled necks, webbed hands, and bulbous, unblinking eyes. Over time, they age very slowly, becoming larger and more fish-like as they do.
They play a significant role in "The Shadow over Innsmouth," where it's revealed that the town of Innsmouth has a dark pact with these beings. The townsfolk worship them and the otherworldly deities they serve, notably Dagon and Hydra. In exchange for prosperity and abundant fish, the townsfolk engage in a ritual of interbreeding with the Deep Ones, producing hybrid offspring. These hybrids appear human in early life but undergo a transformation in their later years, eventually joining the Deep Ones in their underwater cities.
The culture and society of the Deep Ones revolve around their ancient cities beneath the sea and their worship of ancient, powerful deities. They represent the unknown horrors of the deep ocean and the idea of forbidden knowledge in Lovecraft's mythos.