Fantastic Beasts and Where to Find Them: The Sin of Grindelwald has many hidden Easter eggs. Here are some of them: 1. The similarities between Harry Potter and Voldemort: The movie shows the similarities between Harry Potter and Voldemort, including their backgrounds, personalities, and goals. For example, Harry desired power and revenge while Voldemort desired control. 2. Newett and Grindelwald's relationship: In the movie, Newett became a loyal follower of Voldemort but he eventually betrayed him. This echoes the plot of Fantastic Beasts and Where to Find Them, because Grindelwald was also a follower in the first movie, but he eventually betrayed Dumbledore. Technology in the Magic World: The movie showcased some of the technology in the Magic World, such as electronic magic and intelligent machinery. These technologies are very similar to those in the Harry Potter series, indicating that the wizarding world has been modernised. 4 Wizard-Muggle Communication: There are many exchanges between wizards and Muggles in the movie, such as wizard students at Hogwarts and travelers from the outside world. These exchanges showed that the social and cultural differences between wizards and Muggles had gradually disappeared. The adventures of magical animals: There are many magical animals appearing and adventures in the movie. For example, Harry and his friends encounter moles and pythons in the forest. The fact that these magical creatures echo the animals in the Fantastic Beasts and Where to Find Them series shows that this series will continue to explore the world of magical animals.