Jacob the Dog

"...that you had the tail of a German Shepard."
Jacob braced himself on the counter with both hands and began to tense, his body was completely stiff and all he could feel was a massive amount of pressure from the lower part of his back. Jacob lurched throwing his body into the counter as the pain grew more tense, there was a massive ripping noise, more pressure and the sudden growth of a thin hairless tail from the base of his spin as it cut through his trousers.
POOF! The tail puffed up with hair and then the transformation stopped with Jacob reaching back and grabbing his new appendage. The tail was real, he couldn't believe it, but there was no amount of trickery on this planet that could just make him sprout a tail...it was magic, there was no other choice.
Jacob couldn't speak, but Cassy could, she chimed once more, "This is so amazing..."
"This isn't funny Cass!" he shouted suddenly, making her flinch, "You can't just do this to me, look at this, I have a FUCKING TAIL."
"It's really cute," she beamed, "I love German Shepards..."
"That doesn't matter Cass," Jacob was getting angry, "Change me back right now, wish it!"
"I need to think," said Cassy, "I wish you could only talk like a dog."
"What, Cass that's noooooof...that's noooooof, noof, fooonnuff, woof, woof," Jacob lost his voice and began to bark, all he did was bark, he was freaking out at this sudden appearance of magic and he just kept barking like a wild dog. Jacob looked to his girlfriend, tears welling up, and began to whimper like a pet, pleading with her. Cassy looked to his tail, it had folded underneath his legs.
"Awwww....I'm sorry Jacob," she said with a mock pouty face, "I wish you were back to normal."
The tail vanished, Jacob prodded his back in relief to find its absence, he turned to his girlfriend, "Please..." he sighed, "Please don't do that again."
"I think I might take the day off work," Cassy smiled, "I'm really not feeling it today..."
"Wait, what are you going to do?"
Jacob braced himself as she said those two words he was already beginning to hate, "I wish..."