Suggestions by @castingsinmyblood

Jonathan Kent

as George Mitchell in What if this actor played

Justin Hammer

as David Warner in What if this actor played

Saruman the White

as David Warner in What if this actor played

Pierce (The Great Train Robbery)

as Charlie Hunnam in What if this actor played

Atrocitus

as Thomas Haden Church in What if this actor played

Pierce (The Great Train Robbery)

as Cary Elwes in What if this actor played

Jor-El

as Corey Stoll in What if this actor played

Lone Starr

as Cary Elwes in What if this actor played

Nero Wolfe

as Niall MacGinnis in What if this actor played

Fred C. Dobbs

as Gary Sinise in What if this actor played

Kilowog

as Vincent D'Onofrio in What if this actor played

Captain Hook

as Sacha Baron Cohen in What if this actor played

Mystique (Raven Darkhölme)

as Angelina Jolie in What if this actor played

General Chang

as Christoph Waltz in What if this actor played

Master Splinter

as George Takei in What if this actor played

Don Quixote

as Roddy McDowall in What if this actor played

Alpha Trion

as Jonathan Harris in What if this actor played

Wally West/The Flash

as Freddie Prinze Jr. in What if this actor played

Batman (Bruce Wayne)

as Tony Goldwyn in What if this actor played

Vermin

as Bill Moseley in What if this actor played