River Serpent Horn is one of the cores for wands not sold by Ollivanders.

Not much is known about the river serpent horn core. What is known is that when it was paired with a wand of ash wood, it was said to have produced a wand of "exceptional power." That being said, it is possible that this core rivals the power of that of the dragon heartstring, but this is only speculation.

This core has shown a sensitivity to parsel-tongue similar to that of the basilisk horn core, and it resonates with greater power when working in tandem with a sister core of a horn from the same serpent, or possibly simply the same kind of serpent.