The gag in your mouth prevents you from warning the man in time as he gathers all your bonds into one bunch and cuts then all at once.
A huge amount of black latex seeps out from the cuts and covers most of your upper chest. You scream and kick, batting at the latex as it rapidly makes its way up your neck and down your stomach. The man yells out in shock and steps back, yelling about how sorry he is. But you have more important things to worry about as the black latex grows in size and covers everything from the neck down.
Your lower body looks like a giant black grub as the latest moves up your neck and covers your head completely. The huge, hulking mass of latex that is now your body begins to feel warm. You try to fight it but cannot due to the fact that you are no longer in control. The warm darkness suddenly begins to get light as the latex begins shrinking around you, becoming skintight. As it does, it makes alterations.
Your whole body bulks up to one like a bodybuilder's, chisled stomach and back muscles, tight, muscular ass, thick legs and arms, and a broad neck. Your legs crack painfully as the become digitrade and your feet become cat paws with claws at the end. Your hands undergo the same, popping into dextrous paws with claws at the end. Your neck is pushed forward as your nose and mouth push out into a long feline muzzle, pointed cat ears growing on the top sides of your head. Your vision is returned in a bright flash of green slitted pupils. You feel a rumbling in your backside and turn around just in time for a thick feline tail to burst out of your tailbone above your tight ass, hanging down.
You have been transformed into an eight foot tall, muscular black latex panther. You get up off the floor and throw your head back, roaring. Your mind becomes accustomed to your new body. You like how big and powerful it is. You turn and with a low growl see the frightened man cowering against the wall.
You dimly remember him doing something for you, but you push this into the back of your mind as you saunter over and grab the back of the man's collar with your paw, lifting him up and bringing him eye-level with you. You growl again and begin to wonder what you should do with him.