Bryan Cranston as Walter White
This is the big one. Despite (six-year-old spoiler alert!) Walter's death in the 2013 finale of Breaking Bad, rumors continue to swirl that Cranston might make an appearance of some kind in the movie version. The nature of that appearance — if it exists at all — is still a total secret.
Since Breaking Bad wrapped, Cranston has been keeping busy as one of the most in-demand actors in showbiz. He's done significant work on stage, winning two Tonys (for 2014's All the Way and 2019's Network), as well as starring in HBO's adaptation of the former play. Cranston has also expanded his horizons with voice work in the family films Kung Fu Panda 3 and Isle of Dogs.