
Unicorns were special because, up until fairly recently, there was a lot of reason to believe they might actually be real creatures, and there were several people who very much believed it including powerful kings and queens. coming back around to the original question, maybe I actually can answer it as is. It was actually common practice in Europe to take Narwhal horns and pass them off as Unicorn horns, and then make medicine out of them. This is not as strong a comparison to the Rhinocerous as most would think, though. Although, once again with the Rhinocerous comparison, there had been some talk about unicorn horns being used in medicines before the modern fantasy lore. Then, it is later in video games and modern fiction that they started having powerful healing magic attributed to them. It is only later in European lore that they started being depicted as horses, and that was also when we saw them attributed with the ability to sense purity and only allowing pure virgin maidens to ride or even come near them. They were generally depicted as something like a bull with one horn growing from the center of it's head instead of two from the sides.

They are even mentioned in the bible as being renowned for their physical strength, which is where theories of the term referring to the Rhinoceros originated from. Original lore depicted Unicorns as powerful creatures. One of the more interesting things about the Unicorn is how much their original lore differs from later English lore.
