Suggestions by @cw1234

Nathan Fillion

as Preston Northwest in Gravity Falls: Dipper and Mabel Return

Brad Abrell

as Agent Trigger in Gravity Falls: Dipper and Mabel Return

Nick Offerman

as Agent Powers in Gravity Falls: Dipper and Mabel Return

Austin Butler

as Bill Cipher in Gravity Falls (Live Action Film)

Keith Ferguson

as Deputy Durland in Gravity Falls: Dipper and Mabel Return

Kevin Michael Richardson

as Sheriff Blubs in Gravity Falls: Dipper and Mabel Return

Carl Faruolo

as Grenda Grendinator in Gravity Falls: Dipper and Mabel Return

Niki Yang

as Candy Chiu in Gravity Falls: Dipper and Mabel Return

Thurop Van Orman

as Gideon Gleeful in Gravity Falls: Dipper and Mabel Return

Jackie Buscarino

as Pacifica Northwest in Gravity Falls: Dipper and Mabel Return

T.J. Miller

as Robbie Valentino in Gravity Falls: Dipper and Mabel Return

Linda Cardellini

as Wendy Corduroy in Gravity Falls: Dipper and Mabel Return

Alex Hirsch

as Soos in Gravity Falls: Dipper and Mabel Return

Alex Hirsch

as Old Man McGucket in Gravity Falls: Dipper and Mabel Return

J.K. Simmons

as Stanford Pines in Gravity Falls: Dipper and Mabel Return

Alex Hirsch

as Stanley Pines in Gravity Falls: Dipper and Mabel Return

Henry Ian Cusick

as Ward in Gravity Falls: Dipper and Mabel Return

Thomas Jane

as Ward in Gravity Falls: Dipper and Mabel Return

Eric Bana

as Ward in Gravity Falls: Dipper and Mabel Return

Michael Hogan

as Ward in Gravity Falls: Dipper and Mabel Return