Suggestions by @devlinclements

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

Uncle Dan (Migration)

as John Goodman in Roles That Actors / Actresses Were ALMOST Casted

Pam Mallard (Migration)

as Scarlett Johansson in Roles That Actors / Actresses Were ALMOST Casted

Mack Mallard (Migration)

as Elijah Wood in Roles That Actors / Actresses Were ALMOST Casted

Sarabi (The Lion King)

as Jane Fonda in Roles That Actors / Actresses Were ALMOST Casted

Zazu (The Lion King)

as Rik Mayall in Roles That Actors / Actresses Were ALMOST Casted

Timon (The Lion King)

as Billy Crystal in Roles That Actors / Actresses Were ALMOST Casted

FAKE

as Teri Hatcher in Roles That Actors / Actresses Were ALMOST Casted

Scar (Disney)

as Derek Jacobi in Roles That Actors / Actresses Were ALMOST Casted

Queen Gnorga

as Julie Andrews in Roles That Actors / Actresses Were ALMOST Casted

Stanley the Troll

as Robin Williams in Roles That Actors / Actresses Were ALMOST Casted

JoJo McDodd

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

Sour Kangaroo

as Michelle Pfeiffer in Roles That Actors / Actresses Were ALMOST Casted

Horton Hears a Who!

as David Spade in Roles That Actors / Actresses Were ALMOST Casted

Dr. Glickenstein (Igor)

as Christopher Lee in Roles That Actors / Actresses Were ALMOST Casted

King Malbert (Igor)

as Fred Willard in Roles That Actors / Actresses Were ALMOST Casted

Dr. Schadenfreude

as Eric Idle in Roles That Actors / Actresses Were ALMOST Casted

Brain (Igor)

as Matthew Broderick in Roles That Actors / Actresses Were ALMOST Casted

Eva (Igor)

as Jennifer Connelly in Roles That Actors / Actresses Were ALMOST Casted