Venom
From Tardis Wiki, the free Doctor Who reference
Venom was transmitted via snakebites. (TV: Revenge of the Cybermen)
Zygons carried venom sacs in their tongues. (TV: The Day of the Doctor) Similarily, the two-eyed Silurian subspecies possessed venom glands which allowed them to transmit venom via their tongues. (TV: The Hungry Earth)
Jo Jones corrected Jack Harkness when he referred to the venom of the giant maggots as poison. (AUDIO: The Green Life) Jack previously referred to a Millennium Bug "stacked with poison". (TV: Fragments)