"Terror of The Zygons" was novelized by Target in 1976, written by Terrance Dicks, under the title "Doctor Who and the Loch Ness Monster". The book further expounded on the concept of the Zygon "sting," poisonous barbs protruding from their hands, which explains why, in the television episode, the Zygons were able to inflict pain on other beings with a mere touch. (The original shooting script for the episode also included references to the sting but the on-screen portrayal of the concept failed to make it clear to the audience.)