"Erumpent horns, tails, and the Exploding Fluid are all used in potions, though classified Class B Tradeable Materials."
-- Newt Scamander (FB)
Horns, tails, and Exploding Fluid (FB)
Luna Lovegood's father Xenophilius owned an Erumpent Horn that later exploded. They both believed it was the horn of the rare (and possibly imaginary) Crumple-Horned Snorkack (DH20).
Used in Exploding Fluid.
From the Latin ērumpō = to “burst forth”