Suggestions by @cw1234

Tom Hardy

as New Villains in Gravity Falls: Dipper and Mabel Return

Cillian Murphy

as New Villains in Gravity Falls: Dipper and Mabel Return

Til Schweiger

as New Villains in Gravity Falls: Dipper and Mabel Return

Stellan Skarsgård

as New Villains in Gravity Falls: Dipper and Mabel Return

Tim Roth

as New Villains in Gravity Falls: Dipper and Mabel Return

Nicole Kidman

as Priscilla Northwest in Gravity Falls (Live Action Film)

Manu Bennett

as New Villains in Gravity Falls: Dipper and Mabel Return

Sala Baker

as New Villains in Gravity Falls: Dipper and Mabel Return

Lana Parrilla

as New Villains in Gravity Falls: Dipper and Mabel Return

Christina Ricci

as New Villains in Gravity Falls: Dipper and Mabel Return

Kevin Dunn

as Mr Pines in Gravity Falls: Dipper and Mabel Return

Mary Lynn Rajskub

as Mrs Pines in Gravity Falls: Dipper and Mabel Return

John DiMaggio

as Manly Dan in Gravity Falls: Dipper and Mabel Return

James Callis

as Ward in Gravity Falls: Dipper and Mabel Return

Jessica DiCicco

as Tambry in Gravity Falls: Dipper and Mabel Return

Stephen Root

as Bud Gleeful in Gravity Falls: Dipper and Mabel Return

Jennifer Coolidge

as Susan Wentworth in Gravity Falls: Dipper and Mabel Return

Kari Wahlgren

as Priscilla Northwest in Gravity Falls: Dipper and Mabel Return

Nathan Fillion

as Preston Northwest in Gravity Falls: Dipper and Mabel Return

Brad Abrell

as Agent Trigger in Gravity Falls: Dipper and Mabel Return