Items, NPCs, quests, objects and spells of patch 1.12.1, read live from the realm itself.

Wavethrasher Scales

NPC	Level	Zone	Chance
Wavethrasher	52 - 53	Azshara	25.0%
Young Wavethrasher	51 - 52	Azshara	20.0%
Great Wavethrasher	53 - 54	Azshara	10.0%