|"Is this all real? Or has this been happening inside my head?"
The subject of this article is a real-life person, group, company, product, or creative work that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
The Pacific Ocean is the largest ocean in the world, spanning from the Arctic in the north to the Southern Ocean in the south, and from the eastern coasts of Asia and Australia to the western coasts of North America and South America. It is the natural habitat of the sea serpent.