Eldritch horror-themed, dark, eerie, mystical wallpaper, ancient tome-inspired design, worn leather-bound book covers, yellowed parchment pages, cryptic symbols, strange hieroglyphics, otherworldly tentacles, glowing ethereal orbs, swirling misty vortex, dimly lit, ominous atmosphere, heavy shading, high contrast, ornate frames, mysterious artifacts, forbidden knowledge, Lovecraftian horror elements.