Remus Lupin from 'Harry Potter'
Let’s just get this one out of the way. Remus means wolf. Lupin means wolf. His middle name is John, which probably also somehow means wolf. The real plot twist here would’ve been if he were revealed to actually be some other creature, like a sea serpent or a robot.
More specifically, Lupin comes from "lupus," the Latin word for wolf, and Remus refers to the mythological character of lore who was raised by wolves alongside his twin brother, Romulus. It’s also worth noting here that, of the two of them, Remus was the one who was killed.
While I’ve got you here, I also want to point out that Harry was being stalked by a big black dog at a time when a man whose name basically means "Black Dog Star" (Sirius Black) had just escaped wizard prison. He really should’ve worked that one out.
Last one: the Weasley twins. Historically, King George III only became king because of the death of Frederick, Prince of Wales. COINCIDENCE? Probably. But I still want to go back in time and tell my poor, emotionally unprepared self, "CONNECT THE DOTS. YOU DON'T HAVE TO BE BLINDSIDED. THE ANSWER WAS RIGHT IN FRONT OF US THE WHOLE TIME."