Dread Bloom

Dread Blooms are flowers that adorn corpses found across the fields and meadows of Khorne's Bastion Stair. They are strangely exquisite in their appearance, much like a blood-red lily streaked with blackened tendrils. The central part of the flower grows into the shape of a deformed face—the larger and older the bloom, the more detailed and horrific the visage. Dread Blooms release a pungent, intoxicating scent akin to jasmine intermingled with the coppery stench of spilt blood. A person approaching within thirty feet of a Dread Bloom (even plucked) risks succumbing to its powerful scent—a powerful hallucinogen that provokes murderous thoughts. Such a victim attacks anyone, friend or foe, nearby, and continues until he comes to his senses.

Source

 * Warhammer Fantasy RPG 2nd ED -- Tome of Corruption (pg. 205)