The "Innsmouth look" appears in the Cthulhu Mythos story, "The Shadow Over Innsmouth", and refers to a set of physical features that result from the hybridization of Humans with Deep Ones. The "look" is shared by all inhabitants of Innsmouth and its origins are a zealously kept secret.
The characteristic features of Innsmouth's townspeople are:
- great affinity for water and swimming;
- bulging, unblinking, watery eyes;
- acute alopecia;
- resonating, gurgling voices;
- shrivelled necks with strange lines (becoming gills in the end);
- wide mouths with thick lips;
- flat noses;
- tiny ears and;
- squeamous grayish skin
Most people might think these traits are some sort of congenital hereditary trait, but they are actually the symptoms of a very slow metamorphosis. As descendants of both Humans and Deep Ones, the people of Innsmouth undergo a very slow transfomation that might take most of a human lifespan to complete. They are slowly changing into Deep Ones, and with the passage of time, the signs of the transformation are more acute and visible to the naked eye. Children look like regular humans, but as they grow, they will start displaying the unsettling and somewhat repulsive traits that define their inhuman lineage. Other humans may tolerate their standoffish presence, but animals hate them and will not go near them willingly.
In later stages, the transformation becomes too blatant to attribute it to a deformity, making them appear like monstrous humanoid amphibians. For this reason, they stay indoors at all times and all windows are boarded and bricked, however, gurgling and gutural sounds can still be heard through the crevices and walls. Most of the time, the transformation will conclude with a creature indistinguishable from a genuine Deep One, which will indicate that the Innsmouther is ready to join their kin below the surface of the sea. However, in a few cases, the transformation will not be completed, leaving the person in the uncomfortable position of being too human to join the Deep Ones but too monstrous to walk in daylight. The transformation is not only physical, those undergoing the change will experience a progressive mental switch, as they will have a growing sympathy and disposition towards the Deep Ones and their activities; and dreams of themselves walking as Deep Ones will start plaguing them in their sleep and granting them knowledge on their watery kin and atlantean cities.
|“||In the winter of 1930–31, however, the dreams began. They were very sparse and insidious at first, but increased in frequency and vividness as the weeks went by. Great watery spaces opened out before me, and I seemed to wander through titanic sunken porticos and labyrinths of weedy Cyclopean walls with grotesque fishes as my companions. Then the other shapes began to appear, filling me with nameless horror the moment I awoke. But during the dreams they did not horrify me at all—I was one with them; wearing their unhuman trappings, treading their aqueous ways, and praying monstrously at their evil sea-bottom temples.||„|
|~ Robert Olmstead , Shadow over Innsmouth|
Robert Olmstead manages to escape the town, but he gradually overcomes his intense repulsion and horror of Innsmouth and its inhabitants when the dreams of the Deep Ones start seeping into his mind. Knowing and accepting that he is becoming a Deep One as well, he considers that he may even find happiness by joining their ranks.