Suggestions by @automaniac14th

Ron Perlman

as Ironhide in Transformers (Reboot Franchise)

Jim Carrey

as Skids in Transformers (Reboot Franchise)

Steve Martin

as Mudflap in Transformers (Reboot Franchise)

Jet Li

as Blurr in Transformers (Reboot Franchise)

Michael Clarke Duncan

as Ironhide in Transformers (Reboot Franchise)

Kenneth Branagh

as Megatron in Transformers (Reboot Franchise)

Sam Elliott

as Optimus Prime in Transformers (Reboot Franchise)

Hugh Laurie

as Ratchet in Transformers (Reboot Franchise)

R. Lee Ermey

as Kup in Transformers (Reboot Franchise)

Bruce Campbell

as Springer in Transformers (Reboot Franchise)

Doug Bradley

as Shockwave in Transformers (Reboot Franchise)

Alan Rickman

as Megatron in Transformers (Reboot Franchise)

Dave Mustaine

as Soundwave in Transformers (Reboot Franchise)

Alan Rickman

as Shockwave in Transformers (Reboot Franchise)

Keanu Reeves

as Soundwave in Transformers (Reboot Franchise)

Kelsey Grammer

as Megatron in Transformers (Reboot Franchise)

Ralph Fiennes

as Megatron in Transformers (Reboot Franchise)

Hugo Weaving

as Megatron in Transformers (Reboot Franchise)

Mark Harmon

as Optimus Prime in Transformers (Reboot Franchise)

Liam Neeson

as Optimus Prime in Transformers (Reboot Franchise)