Fantastic Beasts 2 - you can read about this here: http://www.independent.co.uk/arts-entertainment/films/news/fantastic-beasts-2-newt-scamander-jk-rowling-patronus-big-spoiler-dumbledore-jude-law-johnny-depp-a7705941.html
Amazing Harry Potter Fan Revelations That Will Make You Rethink Everything
But I dont care either, I dont care! said Tonks, seizing the front of Lupins robes and shaking them. Ive told you a million times.And the meaning of Tonks Patronus and her mouse-colored hair, and the reason she had come running to find Dumbledore when she had heard a rumor someone had been attacked by Greyback, all suddenly became clear to Harry; it had not been Sirius that Tonks had fallen in love with after all. --> This. Is. Perfect.