Suggestions by @rowenjackson

Jack Black

as The Albino in The Princess Bride

J.K. Simmons

as The Impressive Clergyman in The Princess Bride

Rowen Jackson

as The Grandson in The Princess Bride

Kenneth Jackson

as Grandpa/The Narrator in The Princess Bride

Kristen Wiig

as Valerie in The Princess Bride

Martin Short

as Miracle Max in The Princess Bride

Timothy Spall

as Vizzini in The Princess Bride

Dennis Haysbert

as Fezzik the Giant in The Princess Bride

Andy Serkis

as Count Rugen in The Princess Bride

Kevin Kline

as Inigo Montoya in The Princess Bride

Zachary Levi

as Prince Humperdinck in The Princess Bride

Chris Pine

as Westley in The Princess Bride

Zazie Beetz

as Princess Buttercup in The Princess Bride

Gary Oldman

as Viggo in How to Train Your Dragon: Race to the Edge Parody

Liam Neeson

as Ryker in How to Train Your Dragon: Race to the Edge Parody

Will Ferrell

as Dagur in How to Train Your Dragon: Race to the Edge Parody

Emma Thompson

as Gothi in How to Train Your Dragon: Race to the Edge Parody

T.J. Miller

as Tuffnut in How to Train Your Dragon: Race to the Edge Parody

Awkwafina

as Ruffnut in How to Train Your Dragon: Race to the Edge Parody

Christopher Mintz-Plasse

as Fishlegs in How to Train Your Dragon: Race to the Edge Parody