The Unown are Psychic legendary Pokémon that reside in a different dimension, which made their existence debatable until they were recently discovered, and served as villains in their movie appearance.
Unown are small Pokémon. All of them are flat with a black circular design with a white eye. Each Unown have shapes that are base on the letters of the alphabet. However, there are also two other versions of the Unown, one that's shaped like a question mark, while the other is shaped like an explanation point. And unlike the other, the two Unown also have their eye half open.
Spell of the Unown
The Unown are the secondary, later true main antagonists of the film, since they caused the events of the entire movie.
The Unown send Spencer Hale into their dimension when he is researching them. Later, Molly Hale releases some Unown from the stone tiles in a box in her house. The Unown, reading Molly's mind, make her wishes come true, including turning Greenfield into crystal and creating Entei to be Molly's new dad. Because Molly also wants a mother, Entei kidnaps Delia Ketchum.
Eventually, Molly realizes that what she is doing is wrong and she wants to stop, but the power of the Unown is out of control. Entei destroys the psychic energy shield around the Unown, sacrificing himself in the process. The Unown are turned back into stone tiles, and Professor Hale is released from the Unown dimension.