Cinematic 8k wallpaper of a colossal Cthulhu towering near a lighthouse perched on a moss-covered rock; the scene is set amidst a furious, stormy sea. The composition is sharply focused and exudes a sense of megalophobia. The digital painting is extremely detailed, featuring a subtle organic glow emanating from Cthulhu's skin. The photorealistic scene is imbued with cinematic and movie-quality aesthetics, dark and moody ambiance, and intricate lumen reflections. Atmospheric lighting and subsurface scattering enhance the hyperrealism, with an insanely detailed 64k UHD quality that resembles a DSLR capture. Rendered in Unreal Engine 5 and Octane Render, the scene maintains a sharp focus and vividly brings the mythical creature to life, blending artistic flair with high realism.