After a few moments of getting a feel for what it's like to swish your tail around like a cow does, you finally let it come to a rest hanging gently behind you.
"Well, now I know what that squirming feeling was," you think to yourself, blushing as you think back to the snake-like feeling in your pants on the way to the station. You were probably already trying to move your tail without even realizing that's what you were doing--causing all of that pain while it was still trapped in your tight-fitting clothes.
"What am I going to do with this thing?" you ask yourself, picking it back up in one hand and pull it around for another look. But before you can come up with anything, your stomach lurches again and your headache comes back with a vengeance. You reach your free hand up to your aching scalp, and before long the pain becomes so unbearable that you let go of your new tail and fix both hands over your excruciating headache. You start to feel two hard lumps swell up underneath your hands, which start to poke out of your skin with sharp points. You scream.
"Are you okay, sir?" the voice of an employee arrives from the other side of the door. You don't answer.
The pain very slowly subsides, but as it does you feel your hands getting pushed away by the new growths. Your open your eyes and gasp at the long curved horns stretching out of your skull.
After their growth slows to a stop, you trace your hands over them, mesmerized by what you are experiencing. Your horns aren't like the tail: there's no feeling in these things, only hard keratin. There definitely yours, though; you can feel the weight of them sitting there on your head. Your heart sinks as you realize the woman who cursed you may have doomed you to be nothing more than a piece of livestock.
"Sir! Are you alright?" says the voice.
You sigh. You're eventually going to get out of here one way or another. As embarrassing as it is, you might as well step out of here while you're still mostly human. (There's no way the tiny gas station bathroom is going to fit the hefty beast that you may shortly become.) You open the door, accidentally banging it against one of your new horns.
The man looks you in the eye, stumbles back, and runs off at the sight of you: a man with the horns and tail of a cow.