Janis thorn
From Tardis Wiki, the free Doctor Who reference
Janis thorns are small, poisonous thorns used by the Sevateem as weaponry. Janis thorns are thin thorns about the length of a finger, with a poison coated tip. This poison causes first paralysis and then death in humans.
Though there is no naturally occurring cure, an anti-toxin was created by the Fourth Doctor using a bioanalyzer. (DW: The Face of Evil)
Leela frequently used janis thorns. In Victorian London, Leela killed a Chinese assassin threatening the Fourth Doctor with a janis thorn. (DW: The Talons of Weng-Chiang)
