The challenge: can you write a plausible scenario in which Piett has wings and a proboscis?
My reaction: There's a sentient species in the GFFA that meets your requirements, curiously enough.*
Well, then, you asked for this.
Thanks to its sun expanding into a red giant, Rordak was a tectonic wreck. It was also a mineral treasure trove, however, and so the Empire had set up several mining outposts there, and minimized the possible risks for its citizens by using convict labor to operate said mines.
And then, there where the locals.
The Viska, as they called themselves, were sentients of a most peculiar body plan and dietary requirements. Both could be summed up in their common nickname of 'the great bloodsucking fiends of Rordak,' especially if one imagined 'fiends' to be winged creatures.
Being a species that rarely left its ancestral habitat – inhospitable though it was – rumors outstripped known facts about the Viska by a large margin. And yet, Cpt. Piett had been quite certain that the tales about their bite transmitting enough genetic material, plus a potent transferase, to reshape any surviving victims in their image, were nothing but a fantastic superstition.
Judging by the trashing creature in the infirmary, that had been Trooper TK 4738 only a few hours ago, this particular story had a base in fact, unfortunately.
Even more unfortunately, the former stormtrooper had not been the only member of the landing team who had been bitten, when the Viska had attacked the group sent to retrieve an urgently needed batch of barthierum.
The first one, yes, but not the only one, and Piett snatched his hand away from where it had crept subconsciously for the bandage around his own arm. He also made sure not to look at any reflective surfaces, lest his imagination gave him wings and distorted his face into a needle-sharp proboscis.
A sharp hiss against the side of his neck jolted the captain out of the gloomy thoughts.
Piett turned to find a medic with a hypospray behind him, expression just the tiniest bit regretful.
"Apologies, sir," the medic said. "Orders are, everyone bitten is to be sedated."
The world was turning grey before the captain could ask whose orders those were. But not before he could wonder if he would ever wake again as something other than a beast.
/^\I/^\ /^\I/^\ /^\I/^\
Piett … floated.
He … flew.
Great leathery wings spread from his shoulders and carried him across a volcanic wasteland.
Ash and darkness covered most of the land, but life shone bright red against the shadows.
Life. Blood. Food!
He banked and circled closer to a cluster of red. Two-legged creatures, wingless – helpless – prey!
He dove.
At the last moment, one of the two-legs turned and black spread out – like wings! Black spread and red ignited, a piece of red much hotter than any of the lives around.
Hotter than any life. Hot as death!
Piett thrashed. Wrong-wrong-wrong! a part of his mind howled, while the rest of him writhed in the grip of burning-cutting-claws-agony!
Oblivion, when it came, was a mercy.
Originally, the story ended here. If it suits your tastes, stop here until Halloween is over.
/^\I/^\ /^\I/^\ /^\I/^\
Light was, Piett learnt, a cruel and biting thing.
It sparked and arced agonizing flashes straight into his brain, and that was before the captain tried to open his eyes.
Noise wasn't much kinder, and movement … well, movement made Piett realize that his bones were filled with sloshing, red-hot molten metal, for even the slightest twitch hurt!
He must have made some sort of noise at that discovery, for there was more noise and movement – outside of him! – and then a touch against the captain's arm.
Touch hurt, too, but his arm … his arm was just that, not part of any kind of wing structure!
That discovery was worth attempting to brave the light, once more.
Trying to blink his eyes open provoked even more of a commotion around Piett, but after some deeply uncomfortable minutes, the painful flashes dissolved into his chief medical officer and the infirmary around them.
"Welcome back to the land of the living, sir," the ChiefMed said, and then added, more softly, "You gave us quite the scare, sir."
"Wh…?" the captain tried to ask, before his raw throat choked him off.
The doctor reached for a cup of something cool, if a bit slimy, that numbed the worst of the pain as it went down.
"You got bit by one of the native creatures, sir, when the landing team was attacked," the ChiefMed explained readily. "It injected quite the nasty mix of biochemicals."
That sounded ominous. And yet …
"I … dreamed?" Piett questioned.
The doctor snorted. "More like hallucinated violently, sir. Even drugged to the eyeballs, we had to strap you down to keep you from thrashing."
Thrashing. Like the half-transformed stormtrooper – or the thing run afoul of Lord Vader's lightsaber. At least one of those had been a hallucination, obviously, but had both been?
"Survivors?" the captain rasped.
The ChiefMed grimaced briefly. "We lost three men before we had figured out the anti-venom."
Then he lowered his voice even further and added, "His lordship was very insistent, though, that you stay alive, sir. Went back to the planet, even, to collect some fresh venom for analysis."
'Fresh' as in, 'still inside the maws of whatever creature had attacked them,' Piett suspected, if perhaps not a complete creature.
It was a curious feeling, to be valued that much.
And such a relief, to have imagined everything.
*except for the transmittable-by-bite part. ;)