"I want this to be a surprise," Jess said. "You can decide how much of it you want to drink, but just don't peek at the label on the vial." She handed Mary the vial for "Unicorn's Horn."
The catgirl popped the cork and put her sensitive feline nostrils up to it. It smelled like the breeze on a hillside with thousands of beautiful flowers. "Well, it can't be all that bad, can it?" she asked herself. Deciding to take the plunge, she gulped down the entire vial.
A pressure built immediately on her forehead. Feeling the fur there, Mary detected a bump, which was slowly expanding. Soon enough, something hard and sharp burst from that bump and grew straight out of her forehead, twisting as it went. Her paws told her it was smoothly segmented, like ripples in a hard rainbow twist lollipop. Soon it was so long she could even see its tip by pointing her eyes straight up.
Mary had grown an impressive blue-silver unicorn atop her forehead. It was almost two inches thick at its base, and it extended a foot and a half up at a 45-degree angle. Its weight was substantial, and Mary had to work her neck muscles a bit harder to keep her head looking straight forward.
"Maybe I drank a bit too much," Mary guessed.
Jess was beaming. "Oh, Mary, it's beautiful! I'm definitely trying the next vial! Why don't you pick it for me, it seems only fair."