He wasn't in any house. He attended Durmstrang and they expelled him when he pushed the limits of decency when it came to dark magic even by Durmstrang's standards.
If he had gone to Hogwarts, he would be in Slytherin.
The Fantastic Beasts series' antagonist, Grindelwald, is not a Slytherin, as he did not attend Hogwarts, instead attending Durmstrang Institute.
Deathly HallowsEdit
Rita Skeeter's tell-all book about Albus Dumbledore reveals that when young Albus was about 17 years of age, Gellert Grindelwald, also about 17, came to Godric's Hollow to live with his great-aunt Bathilda Bagshot.
Nurmengard Castle was located somewhere in the Austrian Alps, and functioned as a wizarding prison. Originally built by Gellert Grindelwald to hold his opponents, it also served as the base of operations for Grindelwald and his followers.
Dumbledore and Grindelwald only spent about two months together, but the two canonically became lovers in that time. Their relationship was passionate and intense, and each wizard helped shape the philosophies of the other.
Along the way, he learned the truth about Credence: that he was the most powerful weapon in the world, and also his son. “The path has been laid, and he is following it, the trail that will lead him to me,” Grindelwald says about Credence.
Gellert Grindelwald (c. 1883 – March 1998) was a pure or half-blood wizard who is considered to be one of the most powerful and dangerous Dark Wizards of all time, his only superior being Tom Riddle and Riddle's master, Isaac Nasser (who partially took inspiration for his ideals from Grindelwald).
By the time of his death in 1998, during Harry Potter and the Deathly Hallows, Grindelwald was about 116 years old, having lived most of his life in prison.
The year 1979, Gellert Grindelwald is released from his prison in Nurmengard for one night to see the love of his life, Angelina, for the very last time. January 23rd 1980, Angelina gave birth to a tiny baby girl who she named Victoria.
Albus Dumbledore: Gryffindor
Some people show traits from multiple houses, and although Dumbledore is definitely one of those, his passion and courage make him a clear Gryffindor.
At the end of Fantastic Beasts 3 though, Grindelwald attempts to use Avada Kedavra on Credence, but Albus and Aberforth Dumbledore successfully block it using golden magic.
Newton Artemis Fido Scamander is the newest golden boy of Hufflepuff House. Like Hermione, if it weren't for his actions, he would make a good Ravenclaw himself. Using sweet Luna as a Ravenclaw reference, we can see that the Magizoologist shares many of her qualities that coincide with Ravenclaw.
We are sure that Hufflepuffs the world over rejoiced in jubilation when Newt Scamander opened his suitcase to reveal a cheerful, yellow Hufflepuff scarf. Here's how the hero of Fantastic Beasts perfectly represents his Hogwarts house.
In the world of Harry Potter as we know it, there are no recorded instances of a person who was sorted into Hufflepuff ever becoming a Death Eater, or any other kind of Dark Wizard for that matter.
He certainly was unafraid of toil! You may remember the Sorting Hat's verse about Hufflepuffs being just and loyal, patient and true, and unafraid of toil.
According to Pottermore, Scamander was born in 1897, and by the time the third novel takes place it's 1994, putting the textbook author at a grand old age of... 97. Old, but just about feasible that he'd be alive and visiting Hogwarts.
Gellert Grindelwald's bi-colored iris is a condition called Heterochromia, which can be genetic, or acquired through trauma/injury.
But let's not forget Grindelwald actually appeared in the Harry Potter movies: in Harry Potter and the Deathly Hallows Part I, the evil Lord Voldemort (Ralph Fiennes) seeks out the older Grindelwald (played by Michael Byrne) to learn the location of the Elder Wand (Grindelwald is seen possessing this same wand in the ...
An Animagus is still a witch or wizard, and Aurors can fight werewolves like Fenrir Greyback, so it's very unlikely Grindelwald is either of those.
Fantastic Beasts: The Crimes of Grindelwald is a 2018 fantasy film directed by David Yates and written by J. K. Rowling. The sequel to Fantastic Beasts and Where to Find Them (2016), it is the second instalment in the Fantastic Beasts film series and the tenth overall in the Wizarding World franchise.
Why didn't the Potters make the Sacred Twenty-Eight? Potter is a common Muggle surname. Harry's family didn't make the list, according to J.K. Rowling, because 'the anonymous compiler of that supposedly definitive list of pure-bloods suspected that they had sprung from what he considered to be tainted blood'.
Credence Isn't Voldemort's Dad But He Could Be Snape's Grandpa. Before Fantastic Beasts and Where to Find Them came out, it seemed like the story's only real Potter connection would be Newt Scamander's relation to Luna Lovegood and a Dumbledore name-drop.
Grindelwald also apparently lies to Credence at the end of The Crimes of Grindelwald by implying that Dumbledore wants him dead (“Your brother is trying to kill you”) — an obvious lie on Grindelwald's part, since as far as we know, Dumbledore doesn't even know who Credence is.
While Albus was unaware of the child, he said that the boy would have been a part of their lives had he known. Furthermore, he confirms a long-held theory that his sister Ariana, who died during a three-way duel between Albus, Aberforth, and Grindelwald, was an Obscurial like Credence.