Suggestions by @devlinclements

General Shanker

as Willem Dafoe in Roles That Actors / Actresses Were ALMOST Casted

Scorch Supernova

as James Marsden in Roles That Actors / Actresses Were ALMOST Casted

Alameda Slim

as Billy Bob Thornton in Roles That Actors / Actresses Were ALMOST Casted

Buck (Home on the Range)

as Mark Hamill in Roles That Actors / Actresses Were ALMOST Casted

Grace (Home on the Range)

as Alfre Woodward in Roles That Actors / Actresses Were ALMOST Casted

King Gator

as David Alan Grier in Roles That Actors / Actresses Were ALMOST Casted

Annabelle/Whippet Angel

as Helen Mirren in Roles That Actors / Actresses Were ALMOST Casted

Carface Carruthers

as Marlon Brando in Roles That Actors / Actresses Were ALMOST Casted

Noah the Elder

as Richard Griffiths in Roles That Actors / Actresses Were ALMOST Casted

Memphis (Happy Feet)

as Paul Rudd in Roles That Actors / Actresses Were ALMOST Casted

Lovelace(Happy Feet )

as Kelsey Grammer in Roles That Actors / Actresses Were ALMOST Casted

Gloria (Happy Feet)

as Mila Kunis in Roles That Actors / Actresses Were ALMOST Casted

Beta (UP)

as Arsenio Hall in Roles That Actors / Actresses Were ALMOST Casted

Alpha (Up)

as Bronson Pinchot in Roles That Actors / Actresses Were ALMOST Casted

FAKE

as Kevin James in Roles That Actors / Actresses Were ALMOST Casted

King Arthur (Quest for Camelot)

as Michael Caine in Roles That Actors / Actresses Were ALMOST Casted

Bladebeak

as Dana Carvey in Roles That Actors / Actresses Were ALMOST Casted

Griffin (Quest for Camelot)

as Bob Hoskins in Roles That Actors / Actresses Were ALMOST Casted

Sir Ruber

as Rupert Everett in Roles That Actors / Actresses Were ALMOST Casted

Kayley (Quest for Camelot)

as Cate Blanchett in Roles That Actors / Actresses Were ALMOST Casted