Janis thorn

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, which she fired through a blowpipe. In Victorian London, Leela killed a Chinese assassin threatening the Fourth Doctor with a janis thorn. (DW: The Talons of Weng-Chiang)