"This...this isn't happening..." Nikki stuttered as she pulled down the back of her pants and underwear, looking down in disbelief. Sure enough, at the base of Nikki's spine, there was something wriggling and growing. Nikki gaped as it started to stretch out.
"Wow, is that what it looks like when it grows? That's pretty awesome," Jessica commentated, but Nikki was too flabbergasted to reply. Although it was growing nearly as rapidly as Jessica's had, Nikki's tail suddenly stopped when it got a little over 10 inches.
"What happened?" Nikki asked, confused at the sudden halt in proceedings.
"Just wait, it's coming," Jessica grinned, and sure enough, she was right. A moment later, long lustrous hair burst out from Nikki's tail, not short like Jessica's, but growing until it just touched the ground. Like Jessica's tail, the hair of Nikki's tail matched the color of the hair on her head. A moment later, all the nerves and muscles connected, and Nikki's tail began to swish back and forth in discomfort.
"Hehe, no monkey business here, my little pony," Jessica chortled as Nikki stared over her shoulder, reaching back to feel the long, smooth hair that trailed down from her backside. "So, now do you believe, O doubtful one?"
"How--how could you do this?" Nikki finally exploded, her tail going back and forth madly. "What if something goes wrong and we get stuck? We don't even know how this thing works, let alone if it'll let us change back! We could end up as some sort of tailed freaks!"
"Oh c'mon, it doesn't seem that hard to use, and besides, these tails aren't hard to hide," Jessica tried to soothe Nikki, realizing she might have pushed her a little too far. "Anyway, since it works, why not just enjoy it? Aren't you just a little bit curious about what else it can do?"