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

Serrated Petal

NPC	Level	Zone	Chance
Fel Lash Elite	56	Dire Maul	14.1%
Phase Lasher Elite	54 - 55	Dire Maul	14.1%
Death Lash Elite	57 - 58	Dire Maul	13.3%
Whip Lasher	54	Dire Maul	3.49%