Are Pobby and Dingan real? It depends. In the book Pobby and Dingan, Pobby and dingan are Ashmole's little sister's imaginary friends, that might actually be more than imaginary characters in the book. But if they are imaginary or not in the book, does that make them real or not real. "Things that never existed can’t be dead. Right?” This shows how Ashmole didn't think that Pobby and Dingan were real, at least not in the real physical world.
I think that if they are imaginary, they are real. If they are defined as imaginary characters, and not real people, the fact that they exist in ones imagination, makes the characters real. If you think that is God real or not, you might think that it isn't. But what if God is just an imaginary power in our heads, instead of a actual physical person in the sky, does that make God real. I think that it does, because the definition of God is then something that someone believes in, and it is true that someone believes in God, so God is real.