Toadstone

The rare toadstone is another ward against evil spirits, magic, disease, and poisons. Worn mounted in rings or strung on thin metal chains, the toadstone increases toughness against disease or poison. The one thing stopping their widespread use is their limited availability; toadstones are quite rare. On good authority, the most reliable way to gain a toadstone is to place a toad on red cloth. Eventually, the toad will spit out his stone. Those who try this or bloodier techniques rarely have much luck because toads like their stones and don’t give them away easily.

Source
[[Category:T]]
 * Warhammer Fantasy RPG 2nd ED -- Old World Armoury
 * pg. 74