"Generally, my kind doesn't trust humans. A mouse envoy should do," she nods, fluttering around your head.
You cock your head in confusion.
"Wait, why do you mean 'not trusting humans' and 'mouse envoy?' I'm not sure I like the sound of tha-"
The fairy dashes her wings in a full-stop, giggling as a cloud of sparkling dust splashes your face. You hack your lungs out, the invasive substance starting to tingle outward from your face and lungs. You cringe as your muscles contract, your skin prickling with a thousand pins. You heave and double-over, hands on your knees. Stranger still, you see your fingers and arms explode with the faintest fuzz, your nails darken, and your vision shift. You swivel your ears as the fairy floats overhead, circling above you. You glance up only to see her descend in a wide corkscrew, her wings glittering in the sun and always just out of reach.
"What's happening to meeeeee?" you squeak, your voice shrill.
Your butt sways as a foreign sensation registers to your brain; some sort of rear phantom limb. You wiggle the new body part as your eyes blot, pupils expanding.
"A literal mouse? You're making me a mouse?! Are you crazy?!"
The fairy chuckles, dive-bombing past you, "Yes, a mouse. One who can walk around our kingdom without cause for alarm."
You snatch for her, anything to stifle the constant assault on your senses. Chattering your four saber-like teeth in agony, you fall short by a mile.
"No, she's huge," you mutter as she grazes your whiskers. "Why can't I touch her? It's like-"
You can't bring yourself to finish the thought, seeing the crumpled remains of your sleeve flopping over, from what you can believe, is your hand's stubby outline. Diminutive, tiny, and worst of all, dwindling. You follow the sleeve to your shirt, the collar already blocking your periphery. You shriek, a mild whine echoing from your throat as your shirt's bottom scrapes inches away your hollow shoes. Feeling your legs begin to split as you shrank, you shuffle in an attempt to return to return to some degree of comfort. With that, your shoes sway in the few moments they're airborne, free of any structure from your former size. Your legs, remolding and already covered in the same fur on your arms, tingle with a sudden whoosh of air; your pants, no longer supported by your splayed legs, pool to the ground. You groan as your face lengthens, nose quivering with a flurry of new scents. Your enlightening smell floods your nostrils; rather, your former, human odor, as your transformation expedites to completion. You shrink, an audible suction drifting from the drifting sleeved-shirt as it crashes to the ground, settled over your pants and shoes. You cry out, your squeaking trailing your tumble down into your pants and into your boxes. You settle amid the cotton mattress, heart racing as your ears flood with blood. Eyes darting overhead, you gleam the faint trickle of shadow over your shirt as the fairy, pink-eyes gazing, flutters inside. She drifts to the back of the shirt, gliding into a makeshift folded seat. You pad through the darkness of your clothing, approaching her as she shines in the concentrated light from above.
"Not too bad, human. You'll make an excellent envoy."