I Reincarnated As A Cosmic Horror

I Reincarnated as a Cosmic Horror (And Everyone Thinks I'm the Demon Lord)When Thomas died, he expected an afterlife—not six needle-sharp legs, a crown of sensing quills, and a giant glowing red sac full of unknown biology.Reincarnated into a sword-and-magic fantasy world governed by a strict System, Thomas quickly realizes he has a small problem: his new body doesn't fit into the local ecosystem. He leaks a bio-luminescent mist that mutates local wildlife, his multi-jointed claws dissect monsters in seconds, and every time he tries to speak, all anyone hears is a bone-chilling chittering that causes localized panic.Thomas just wants to figure out his alien anatomy, explore this weird new world, and maybe find a quiet place to exist.Unfortunately, his first attempt to wave hello to a group of low-rank adventurers sends them screaming into the night. Within weeks, the local kingdom panics, a Holy Crusade is organized, and outcasts from across the continent begin gathering at his cavern, worshipping him as a harbinger of the end times.Worst of all? The System keeps updating his title: [Extramundane Calamity].To survive the knights at his door and the cultists at his feet, Thomas will have to learn how to bio-engineer his alien traits, adapt his ecology, and accidentally rule the world—whether he wants to or not.What to Expect:Non-Humanoid Protagonist: A true monster/alien MC with unique sensory, biological, and evolution mechanics.Misunderstanding & Culture Shock: A rational, normal guy stuck in an eldritch body, surrounded by people who think he's a 10,000-year-old evil mastermind.Ecology & Base Building: Spreading a bio-domain, mutating local flora/fauna, and building an unwilling sanctuary.LitRPG / Progression: System notifications, biological evolutions, and scaling power.No Instant Harem / Rational MC.