The villains (or demons) of Spirit track.
First at the bottom we have kinda boring design of malladus spirit, which basically is a blue head.
Above that we have Malladus in Zelda's dead cold body.
Then there's the Ganon train as I call it (ganon is not mentioned in the game), who is an evil train, called the demon train.
Then there is that squealing leprechaun, don't steal his lucky chaarms!!. He's trying to make himself more trustworthy by wearing two top hat, Not suspicious at all!. Also I did give him a gold tooth, hard to see here. But here's a closeup: https://38.media.tumblr.com/8acae42c439029230b1b32b81388e168/tumblr_nbch6pLNkt1qcm40po1_500.jpg
And on the top we have the final boss, He is, well. Lets just say he's a merge of two people =P.