Heartkill

Certain potent venoms become even deadlier when mixed. Such is the case of the amphisbaena (the two- headed serpent) and jabberwock venom. When blended, these toxins form a colourless, odourless liquid, virtually undetectable when placed in food or drink. After imbibing, the poison kills when it reaches the victim's heart.

Source
[[Category:H]]
 * Warhammer Fantasy RPG 2nd ED -- Old World Armoury
 * pg. 72