Suggestions by @kalrim_frosthill

Ian McKellen

as Hekaton in Storm King's Thunder

Patrick Stewart

as Hekaton in Storm King's Thunder

Sean Connery

as Hekaton in Storm King's Thunder

Nicol Williamson

as Hekaton in Storm King's Thunder

Rebecca Black

as Leyan Melody in Storm King's Thunder

Amber Heard

as Leyan melody in Storm King's Thunder

J.K. Simmons

as Lorn au Arcos in Red Rising

Jeremy Elbertson

as King Jeremiah in Storm King's Thunder

Rachel Weisz

as Iymrith in Storm King's Thunder

Freya Allan

as Chezzaran in Storm King's Thunder

Millie Bobby Brown

as Anaxaster in Storm King's Thunder

Diana Rigg

as Laeral Silverhand in Storm King's Thunder

Vinesauce

as Large Luigi in Storm King's Thunder

Benedict Cumberbatch

as Klauth in Storm King's Thunder

Sacha Baron Cohen

as Commodore Krux in Storm King's Thunder

Tom Kenny

as Aboleth in Storm King's Thunder

Hugh Jackman

as Durnan in Storm King's Thunder

Bruce Campbell

as Mirt the Moneylender in Storm King's Thunder

Elliot Page

as Xeleth in Storm King's Thunder

Danny DeVito

as Aurinax in Storm King's Thunder