Pennywise comes from Stephen King’s IT mythos as an ancient, interdimensional entity linked to a cosmic place called the Macroverse. In the story, IT inhabits a deathless, void-like realm and occasionally enters our universe, often surfacing in the town of Derry, Maine. Its true form is not a clown but a shapeshifting creature that feeds on fear, especially of children, awakening in cycles of several decades. The backstory ties Pennywise to the larger IT creature and the broader cosmic framework King uses for many of his monsters.