fantasy cast
A list of players, usually movie stars, for the roles in a book, comic, or other favorite story. Choosing the actors is called fantasy casting. People participate in fantasy casting as an exercise in "what-if" movie making. Also called a dream cast.
Here's a popular fantasy cast for 'To Kill A Mockingbird': Mel Gibson for Atticus Finch, Abigail Breslin for Scout Finch, Johnny Depp for Boo Radley, and Don Cheadle for Tom Robinson.