Basilisk wands are incredibly rare, as the beasts are rare to begin with and hard to kill. Due to the rarity, they often are passed down from generation to generation, so basilisk-core wands are either the heirloom of Slytherin-type Pureblood families or reforged wands from family cores. The occasional new basilisk wand will almost always bond to a Parselmouth or budding Dark Wizard. Very little good comes out of wielders of basilisk wands.