Hark/Toad
As it stands in the finished film, the character of Toad is introduced as a protesting singer and is later de-evolved into a rebellious Goomba that assists both Daisy and the Mario Bros. in thwarting King Koopa. However, most people don't know that Toad's role was originally split between two characters. Toad was originally planned to de-evolve into slime (effectively killing him off), while an already established Goomba--Hark--would aid Daisy in the tower.
Thanks to MEL (Makeup & Effects Laboratory), we now know what Hark would have looked like had his role remained unchanged. A more aggressive facial sculpt and a flashier, more regal uniform (similar to the original Goomba concept art) provide a fascinating insight into the development of this character. And of course, there are lots of great photographs here of "Goomba Toad" once the roles were merged.
Concept Artwork
Sculpts (Un-painted)
Sculpts (Painted)
Mechanical Workings
Costumes
Related Links:
SMB Archive's Interview with MEL (Makeup & Effects Laboratory)