Dan just stood there a moment in shock. His sister was actually going to let him turn all the way into an animal. Couldn't she have just seen he was scared and took the curse off? He could have maybe tried to apologize to her, and promise to be a better brother, but no, she wouldn't even give him the chance to talk.
"If this keeps up, I won't even be able to talk anymore," he thought to himself, quivering. He took a few steps back to his room and then jumped when he felt a sudden twitching in his pants. At first, it was like a muscle spasm right above his butt, but then he realized he could control it. By the time he got his pants pulled down in the back and touched his right hand to the worrisome spot, there was already a thick knob longer than a pencil sticking out there. Dan gasped as he realized what was happening.
'Oh no, not that, anything but that, I can't be growing a ...'
Suddenly, Dan and groaned had to let go of his twitching nub as sudden shift made him hunch over and clutch his torso. His spine felt weird as it built new bones only to shove them out behind him, stretching out his new accessory in the process. It was like filling up a balloon from out of his midsection. When it was finally over, he perked himself up and twisted around to check on the freshly grown swinging mass behind him. He almost fainted when he saw it.
It was long and covered with jet-black fur, hanging low between his legs with a fluffy black tassel on the end.
'It's like a cow's or a bull's, but it's mine,' he thought, waving it around, staring at it with wide eyes. He gripped a hand around it and lifted, feeling its muscular heft. He sat down gently on the bed, so he could catch his breath and examine the appendage more thoroughly. Feeling his own two hands on different parts of a tail that didn't exist two minutes ago was an almost hypnotizing experienced. He took deep breaths and calmed down a little bit but didn't cheer up at all.
"I don't want a tail," he mumbled out loud to know one in particular.
Of course, with a moment's thought Dan realized why he was going to need one. Livestock basically had to mostly stand around all day with no hands, getting muddy and releasing their bodily functions wherever they stood. They'd get overwhelmed with flies if they didn't also stand around swatting them away almost constantly. Dan sulked as he realized just how low he was going to fall.
'She's really going to do it,' he thought. 'My own sister's gonna just leave me as a barnyard animal, with nothing to do and nothing but my own tail to handle an itch.'