The balloon gently floating above you gives out a squeak as its tail pulls in to its cow torso, disappearing.
Trevor stands watching with his mouth hanging open staring at the balloon. With a sensation of pressure on your spine you feel your little swimsuit get tighter, then relax suddenly as your new tail pushes its way over your wasitband just above your butt crack. Its smooth and cold to the touch, squishy like a balloon as you reach behind you and probe it with your shaky hands.
"I dont like this... I... ugh... mooooooo!" you are unable to finish your sentance as your ability to speak is suddenly altered.
The balloon above you stands upright, its back straightening and its little tube like legs shifting to look more like a persons legs. As it stands you feel your spine ache and your weight falls forward as you are thrust to your hands and knees.
"Holy shit man... you are turning in to a cow balloon and that balloon is... um... I think its turning in to you!" Trevor backs up and slams his back in to the line of lockers behind him without thinking. The look of panic in his eyes reminds you of how horrible this must look to him. To you, it feels very strange. A bit painful but mostly its new sensations you never experienced before as your skin turns to red latex and your insides gently vanish being displaced by air, filling your balloon body.
"Mooo get... mmmmooo help." you struggle to speak. Trevor cant understand you.
Above you the balloons hooves shape themselves in to hands and feet as your hands clench in to fists that melt together with a squeak forming rubber hooves, your feet shrink as your legs stiffen and your knees vanish forming little back legs of a balloon cow.
Your dick inflates with a hiss as your balls change, and then the lot is absorbed back in to you as you become generderless, a rubber cow like the rubber man above you, only as you change, so does it, and it now has a tiny set of genitals in its red rubber body.
With a final moan your chest inflates growing large and barrel like, that of a cow. Your arms and head were largely unchanged except for the hooves and horns, but now your arms begin to shrink and inflate as your face pushes outward forming your new muzzle.
Above you the cow balloon does indeed look like you, only rendered in red latex, a balloon you to match the new balloon-cow you. Its like being in two places at once.
Your changes complete and before Trevor stands a giant balloon cow and with a swoosh it becomes an eighth of its size and a little string grows out of your neck to tether you as you float up to the ceiling and bump gently.
Trevor closes his mouth and stares at both balloons wonder what to do.