Since the update to the PC1.3 equivalent, any existing Sparkly Wings in a player's inventory are replaced by Cenx's Wings upon loading the game.
There are 18 sets, so each set has around a 0.3% chance of being obtained from a given treasure bag.
Trivia[]
Developer items, along with 0x33's Aviators, are the only Expert-exclusive items that do not have the Rainbow rarity.
Some items (unlisted) were used by the developers during game testing, and were removed from normal gameplay, making them unobtainable: Red Potion and Zapinator (the Zapinator was later released on 3DS, a different version of the Zapinator was re-released in 1.4.0.1, and the Red Potion is available in 1.4.0.1 worlds with the seeds "05162020" or "for the worthy").
The developer items were unobtainable before the 1.3.0.1 update, and, if somehow worn, most of the items would inflict a variety of debuffs on the wearer, even if worn in the vanity slot, thus rendering them useless. One of the exceptions to this rule were Red's Wings, which would give infinite flight when worn.