The Great Intelligence was originally created by Henry Lincoln and Mervyn Haisman and first appeared in the 1967 serial The Abominable Snowmen where it encountered the Second Doctor and his companions Jamie and Victoria.

The 1967 serial The Abominable Snowmen depicts the Great Intelligence as having possessed the body of the High Lama Padmasamabhava (Wolfe Morris), ever since encountering the man on the astral plane some centuries ago.

[2] In the sequel The Web of Fear, aired in 1968 and set forty years after The Abominable Snowmen, the Great Intelligence returns when a control sphere is activated and enters a Yeti.

The Great Intelligence uses a woman called Miss Kizlet (Celia Imrie) to aid him in creating an organization based at the Shard to collect and harvest the minds of people using Wi-Fi for it to feed on.

[5] In the Series 7 finale, "The Name of the Doctor", the Great Intelligence manifests through and manipulates dark creatures called the Whisper Men, changing the one it inhabits into the form of Dr Simeon.

The Great Intelligence also features in several novels (All-Consuming Fire, Millennial Rites, Business Unusual, The Quantum Archangel and Divided Loyalties) in which it is identified with H. P. Lovecraft's Yog-Sothoth, a being from the universe before this one.

The Great Intelligence could also manifest itself in simple forms such as a slime that glowed brightly, a dense fog that consumed anything that entered it, and a poisonous web/fungus that could trap the Doctor's TARDIS and could not be destroyed by chemicals, explosives or flamethrowers.

The Yeti were an effort by the production team to create more recurring antagonists for the Doctor in lieu of the Daleks, whose creator and part-copyright owner Terry Nation desired to have appear in an American spin-off series.

[5] Steven Moffat said that he wrote "The Bells of Saint John" as an "action rollercoaster", with the Spoonhead robots devised in contrast to other monsters he had created such as the Weeping Angels and Silence with a focus on scares.

The Great Intelligence is able to physically manifest in place of any of the individual Whisper Men, taking the form of his last human host, Walter Simeon (Richard E. Grant).

Critic Graham Sleight commented in an analysis of Doctor Who monsters that the use of Yeti robots by the Great Intelligence was uninteresting as they provided merely a physical and voiceless threat.

Patrick Mulkern, writing for Radio Times, said "hats off to Steven Moffat" for reintroducing the character and described the casting of Ian McKellen as "a coup" and "wizardly".

[14] The character was seen by some reviewers as being underdeveloped, with Kyle Anderson of the Nerdist feeling that although McKellen and Richard E. Grant, who portrayed its human minion Dr Simeon, were excellent casting choices the Great Intelligence's plan was "the least fleshed out part of the script".

[15] Matt Risley's review on IGN similarly praised the acting of McKellen and Grant, but felt the story was "stuffed with ideas" and the Great Intelligence's return was overshadowed by the "fully formed and utterly unpredictable" performance of Jenna-Louise Coleman as Clara Oswald.

[18] Neela Debnath of The Independent, despite feeling that the episode was a "rehash" of elements of "Blink" and Sherlock, commented that it appeared to be establishing the groundwork for a battle between the Doctor and Great Intelligence.