Suggestions by @jahshaman

Alfie Allen

as Cletus Kasady in Spiderman 4

Michael Stuhlbarg

as Otto Octavius in Spiderman 4

Cliff Curtis

as King Shark in Casting James Gunn's DCU! :D

Javier Bardem

as Darkseid in Casting James Gunn's DCU! :D

Joel Edgerton

as Captain Boomerang in Casting James Gunn's DCU! :D

Bill Hader

as Plastic Man in Casting James Gunn's DCU! :D

Andy Samberg

as Booster Gold in Casting James Gunn's DCU! :D

Grace Van Dien

as Starfire in Casting James Gunn's DCU! :D

Damian Lewis

as The Question in Casting James Gunn's DCU! :D

Jude Law

as Red Tornado in Casting James Gunn's DCU! :D

Nico Parker

as Miss Martian in Casting James Gunn's DCU! :D

Katheryn Winnick

as Black Canary in Casting James Gunn's DCU! :D

Charlie Hunnam

as Green Arrow in Casting James Gunn's DCU! :D

Ricky Whittle

as Hawkman in Casting James Gunn's DCU! :D

Sarah Gadon

as Queen Mera in Casting James Gunn's DCU! :D

Patrick Wilson

as Alan Scott in Casting James Gunn's DCU! :D

Iain Glen

as Alan Scott in Casting James Gunn's DCU! :D

Khary Payton

as Gorilla Grodd in Casting James Gunn's DCU! :D

Winston Duke

as Gorilla Grodd in Casting James Gunn's DCU! :D

Theo Rossi

as Captain Cold in Casting James Gunn's DCU! :D