This is a real tooth from a Zuul ankylosaurid dinosaur!
Zuul is a genus of anklyosaurian dinosaurs from the Late Cretaceous of North America. They resembled the more iconic anklyosaurs, but lacked the distinctive tail clubs.
These fossil teeth are from the Judith River Formation of Montana and date back to ~79-74 million years before present.
They come framed in a ~3.25" wide riker mount and can be shipped worldwide.