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

When a goo pony dies their core will be left behind. Over thousands of years it can crystalize, but be very careful not to touch it or you'll turn into a goo pony in an instant :P

And the rest:
"Regular form":/2608229
"Harpy form":/2608231
"Inflatable form":/2608232
"Skunk form":/2608234
"Lamia form":/2608235
"Portrageist form":/2608237
"Siren form":/2608240
Goo pony form
"Twilight Sparkle form":/2608248
"Zebra form":/2608251
"BONUS: LIVING DRESS":/2608252
"BONUS: SHADOWBOLT":/2608254