"Elephant in the Room" was the first series theme; it first appeared in "Engineering". This was a joker card given to each panellist, used in every E Series episode apart from the finale. They were instructed to use it if they thought the answer to a question was related to elephants; every episode contained at least one elephant-related question.
A panellist gained 10 points if they correctly used the card; it is unknown if they lost points for using it incorrectly. It was not revealed how many points later jokers were worth, but some lost contestants points when they were used incorrectly.
The name of the joker, "Elephant in the Room", is a joke based on an English idiom: an 'elephant in the room' is an obvious thought that no-one is willing to address.