Suggestions by @jesselee

Iago (Aladdin)

as Iago in Tuff puppy

M.O.D.O.K. (George Tarleton)

as M.O.D.O.K. in Tuff puppy

Emma Watson

as Emma Frost in Tuff puppy

Madame Hydra/Viper

as Madame Viper / Hydra in Tuff puppy

Galactus

as Galactus in Tuff puppy

Minnie Mouse

as Minnie Mouse in Tuff puppy

The Riddler (Edward Nigma)

as The Riddler in Tuff puppy

The Penguin (Oswald Cobblepot)

as The Penguin in Tuff puppy

Gaston LeGume

as Gaston in Tuff puppy

Doctor Victor von Doom

as Doctor Doom in Tuff puppy

Ichabod Crane

as Ichabod Crane in Tuff puppy

The Headless Horseman

as The Headless Horseman in Tuff puppy

Sheldon J. Plankton

as Plankton in Tuff puppy

KA.R.E.N. the Computer Wife

as KA.R.E.N. the Computer Wife in Tuff puppy

Hades (Disney)

as Hades in Tuff puppy

Old Hag

as Old Hag in Tuff puppy

Magic Mirror

as Magic Mirror in Tuff puppy

Chernabog

as Chernabog in Tuff puppy

Maleficent (Disney)

as Maleficent in Tuff puppy

Donald Duck

as Donald Duck in Tuff puppy