One fine morning, Spike woke up early and ran some errands. Then he found Discord putting up a seller's stand, apparently ready to open his own business. One which offers a one-day transformation into anything the user wants. And he apparently had the patience to set up his shop LEGALLY. Twilight and the others brace themselves for the inevitable...

(Content of future chapters controlled by user votes!) (Now with Tropes!)

Now with a 'dramatic' reading: Prologue

Current poll: The transformation is chosen already (Tatzlpony!) You pick who becomes the Tatzlpony! (Voting ends 6/25 at 5PM EST)
Previous poll: The Cutie Mark Crusaders (63 votes out of 390) and Age Manipulation (83 votes out of 392) won
Previous poll: Sunset Shimmer (transformation error won with 83 votes out of 325)
Previous poll: Princess Celestia (85 votes out of 397) and Seapony/Siren (104 votes out of 421) won
Previous poll: Trixie (86 votes out of 357) and Alicorn (90 votes out of 338) won
Previous poll: Fancy Pants and Fleur Dis Lee (genderswap won with 199 votes out of 381)
Previous poll: Princess Luna (zebra won with 85 votes out of 368)
Previous poll: Rainbow Dash (griffon won with 274 votes out of 596!!!)
Previous poll: Rarity (diamond dog won with 184 votes out of 444!!!)
Previous poll: Starlight Glimmer (changeling royal (Chrysalis-type) won with 74 votes out of 257)
Previous poll: Pinkie Pie (alicorn won with 80 votes out 282)
Previous poll: Spike (unicorn won with 60 votes out of 225)
Previous poll: Applejack (minotaur won with 56 votes out of 254)
Previous poll: Fluttershy (draconequus won with 75 votes out of 181)

(Voting closes after a week from the posting of the current chapter)