Here comes a whole bunch of Star Tracker transformation pics. His crossdressing cosplay sees him trying to find all sorts of little odds and ends he can use in his outfits, and more than a few times he's gotten his hooves on a cursed item that transforms him :D

A blue gemstone made of concentrated skunk spray that crystallized like amber over thousands of years. It doesn't smell, but it does transform :P

And the rest:
Regular form
Harpy form
Inflatable form
Skunk form
Lamia form
Portrageist form
Siren form
Goo pony form
Twilight Sparkle form
Zebra form
BONUS: LIVING DRESS
BONUS: SHADOWBOLT