Cinematic 8k wallpaper featuring a colossal Cthulhu, centered composition near an ancient lighthouse on rugged, moss-covered rocks, with a violently stormy sea in the background. The scene is in sharp focus, emphasizing a sense of megalophobia, rendered as an extremely detailed 4k digital painting. The creature emits a subtle organic glow with photorealistic textures, creating a dark and moody atmosphere. Lumen reflections and atmospheric lighting add depth, with subsurface scattering enhancing the hyperrealism. The scene is rendered with insane detail and highly realistic features, akin to a 64k UHD DSLR photograph. Made with Unreal Engine 5 and Octane Render technology, the image boasts an 8k quality with cinematic movie-grade details.