underwater nightmare with ugly human creature

abyss abyssal alarming algae anguish aquaman artistic atmosphere bad bloodcurdling breathing bubble chilling creature creepy dark darkness death diving dream drowning fish focus gothic hair hairy hallucination human incubus long man mermaid merman night nightmare ocean octopus oxygen pic pool portrait scary scuba sea sink siren strange submarine submerged succubus sunken swimming terror ugly undersea underwater water waterfall