Yes, it might exist in some fanfiction. A possible plotline could be a comical one where Naruto is put in a situation where he has to take care of a baby and accidentally ends up with a pacifier in his mouth while trying to soothe the baby. Another could be in a more AU (alternate universe) setting where Naruto is a child again and has a pacifier as part of his new, different childhood story.
Perhaps in the fanfiction, the pacifier is a magical item. It could be that Naruto discovers the pacifier and when he uses it, he gains some sort of unique power. For example, it might allow him to communicate with animals in a new way or give him enhanced strength but only when the pacifier is in his mouth. This would lead to some interesting situations where he has to keep the pacifier safe while using its power to fight enemies.
A possible plotline could be that Naruto's mother returns from the dead in some way. This could create a huge stir in the ninja world. Naruto would have to deal with his new - found family situation while also facing the challenges that come with it. There could be enemies who target his mother because of her connection to Naruto or some secrets she holds. And Naruto would have to learn to balance his relationship with his mother and his duties as a ninja.
One possible plotline could be that Naruto's brother has been living in secret all this time. Maybe he was sent away for his own safety when they were young. He could return to the village and at first Naruto is suspicious, but as they get to know each other, they form a strong bond and fight together against the common enemies of the village.
Maybe Naruto's bat wings are a gift from a mysterious being. This gives him an edge in his ninja missions. He might start exploring caves and other dark places that normal ninjas can't reach easily with his new ability to fly. His friends might be a bit jealous at first but then see how useful it can be for the team as a whole.
One possible plotline could be that the older brother was thought to be dead but actually survived and returns to protect Naruto from the shadows. He might have some special powers or knowledge that he uses to keep Naruto safe without revealing his identity at first.
Maybe Naruto's death powers are a result of some ancient curse or a powerful jutsu gone wrong. This could lead to a plot where he has to find a way to reverse it, while also using it to protect his village. He might encounter other shinobi who have similar powers and learn from them how to use it more effectively.
A really different take could be that the pacifier is a gift from an enemy. But instead of being harmful, it actually has a positive effect on Naruto. It might be a way for the enemy to test Naruto's character or to see if he can be tamed. And Naruto, being Naruto, finds a way to turn this strange situation into an advantage, making for an interesting and unexpected plot twist.
Well, it really depends on the specific fanfiction. There are countless Naruto fanfictions out there, and some writers like to add really out - there elements to the characters. A scorpion tail for Naruto could be a really interesting concept. Maybe it gives him new powers like being able to use poison or have a stronger attack. But not all fanfictions will have this idea, so you have to search through different ones to find it if you're interested.
Perhaps they could start a training program for young ninjas from both their villages. This would not only strengthen the bond between their villages but also give them a chance to teach the next generation their values. In the process, they'd face challenges from traditionalists who don't want to change the old ways.
Maybe the horns are a sign of a new power awakening within Naruto. He could initially be afraid of them and hide them, but as he discovers their potential, he learns to embrace this new aspect of himself and use it to protect the village in ways he couldn't before.