Bad Wolf was a meme created by "the Bad Wolf" to inspire Rose Tyler to save the Ninth Doctor from the Game Station. (TV: The Parting of the Ways) It also prefigured the return of Rose into the Tenth Doctor's life, following his regeneration, as well as the crisis they would face together. (TV: Turn Left) "Bad Wolf" was thus both warning for the end of the universe and signpost.
When the consciousness of the Moment took form, it selected the form of Rose Tyler as the Bad Wolf entity. When the War Doctor commented that he could kiss her for giving him a way out of the dual-genocide he was prepared to commit, she remarked, "That's definitely gonna happen." The Tenth and Eleventh Doctors, having already heard the Bad Wolf meme, were visibly surprised to hear his past self mention "Bad Wolf girl", as she was only visible and audible to the War Doctor. Due to the timelines rearranging themselves, the War Doctor (and his immediate successor) retained no memory of Bad Wolf. (TV: The Day of the Doctor)
During the Doctor's ninth incarnation
TARDIS graffiti was the Doctor's first known direct encounter with the phrase. The phrase was most commonly found in graffiti during the 20th and 21st centuries, (TV: Aliens of London, Father's Day, The Parting of the Ways, Captain Jack Harkness, PROSE: Rose) but the first chronological occurrence was in 1592, where a tavern sign showed a picture of a wolf's head and the initials "B.W.". (COMIC: A Groatsworth of Wit) It later occurred in 1869, when Gwyneth, a parlour maid and clairvoyant, looked into Rose's mind and declared she had seen "the Big Bad Wolf". (TV: The Unquiet Dead)
The first occurrence of the phrase in the Doctor's and Rose's timestream was in the year 5,000,000,000 on Platform One orbiting the soon-to-be-destroyed Earth. The Moxx of Balhoon told the Face of Boe that the current situation was "the Bad Wolf scenario". (TV: The End of the World) Bad Wolf was on one of the posters for ENERGIZE. (TV: Father's Day)
It appeared in other languages as well. It was used on a type of Nazi artillery shell in World War II, the "Schlechter Wolf" (TV: The Doctor Dances, PROSE: Unexploded WWII Bomb Warnings) and a nuclear power station built in September 2006, the Blaidd Drwg power station. (TV: Boom Town, PROSE: Cardiff Earthquake)
At least one company, GeoComTex, used the phrase "Bad Wolf" as a helicopter call sign; Henry van Statten's private helicopter was "Bad Wolf One". (TV: Dalek). Another company, Bad Wolf Holdings, was a part of the Consortium in New Vegas in the 23rd century. (AUDIO: Night of the Whisper)
The phrase became more common in the years 199,909 to 200,100, when the Dalek-controlled Bad Wolf Corporation and the television channel "Bad WolfTV" made use of it. (TV: The Long Game, Bad Wolf / The Parting of the Ways)
It turned out that to save the Doctor's life, Rose Tyler had opened the Doctor's TARDIS, looked into its heart and become the Bad Wolf entity. She then used her seemingly unlimited reality-warping powers to destroy the Dalek Imperial Fleet and spread the Bad Wolf meme throughout space and time, so she would realise she could use the TARDIS to save the Doctor (thereby creating an ontological paradox). Rose was later restored when the Doctor saved her life by taking the Time Vortex energy from the heart of the TARDIS out of her body and regenerating. (TV: The Parting of the Ways, Children in Need Special)
The band No Hot Ashes, which Mickey, Sally Salter, (PROSE: Rose, AUDIO: Ghosts) and Jimmy Stone were members of, (PROSE: Meet Rose) was renamed to Bad Wolf on 5 March 2005 after Sally had seen the term used in graffiti in a car park on Jordan Road. (PROSE: Rose)
After Bad Wolf
Although the influence that had created the Bad Wolf meme had been removed from Rose by the time of the Doctor's regeneration, echoes remained. The playground chalk drawing of "Bad Wolf" was still faintly visible after he and Rose left to visit New Earth. (TV: New Earth)
In 1879, the Host, a human boy under control of a werewolf's bite, stated that Rose had "something of the wolf about her." Because the wolf was also very hostile, it could be considered a literal interpretation of the Bad Wolf. (TV: Tooth and Claw) The Torchwood Institute's files on Rose Tyler were corrupted by the Bad Wolf virus (TV: Love & Monsters) and, after the Doctor and Rose had been separated in different universes, the last hole through the Void linking them led into "Dårlig Ulv Stranden" (Bad Wolf Bay) in Norway. (TV: Doomsday) It also appeared in the year 5,000,000,053, inside a New New York car. (TV: Gridlock)
On a parallel Earth, Donna Noble was sent back in time to make her past self in the "main" reality turn left at a junction on Little Sutton Street. She did this by running into a lorry, creating a traffic jam. As Donna died, Rose told Donna to tell the Doctor two words: "Bad Wolf". The "real" Donna vaguely remembered the words whispered to her other self, which she told to the Tenth Doctor. Immediately, the whole of Shan Shen was covered with the words "bad wolf". Even the Doctor's TARDIS was altered to include the phrase on all of its exterior signs. Donna asked what this meant, and the Doctor told her it meant the end of the universe. (TV: Turn Left)
The words "Bad Wolf" appeared in graffiti on the landing of the Ritz stairway, shortly before Jack Harkness and Toshiko Sato were sent backwards in time to 1941. (TV: Captain Jack Harkness) At around the same time, Cardiff had a motorcycle gang Blaidd Drwg. (COMIC: Jetsam)
Behind the scenes
- A clip whoisdoctorwho.co.uk identified the newsreader who reported the spaceship crash into Big Ben as "Mal Loup", (approximative) French for "Bad Wolf".  Mickey also described the Ninth Doctor on the same site as "making another decision for us, all 'I'm the big bad wolf and it's way past your bedtime.'" 
- In the FAQ of the Geocomtex website, the correct sequence of the pins in the first question is Morse Code for badwolf. 
- In Captain Jack's Monster Files for the Trickster's Brigade on the official website, one of the many squares on the board game, seen around 2:52 into the video, shows Bad Wolf. 
In an animated reconstruction of a scene from The Invasion from that story's DVD release, "Bad Wolf" appears as graffiti on Isobel Watkins's wall. (The character liked to write reminder notes for herself on the wall.)
In The Power of the Daleks, another animated second Doctor story, "Bad Wolf" appears on the colony notice board.
"Bad Wolf" appears, albeit backwards, on the eye testing board in the animated version of The Faceless Ones.
Information from invalid sources
- Technically, the closer German translation for the term is "Böser Wolf", the name of the character in the Brothers Grimm fairy tale, "Little Red Riding Hood". "Schlechter Wolf" implies a wolf of inferior quality.
- US News Report. BBC Media Player. Retrieved on 24 July 2013.
- Smith, M. Hoax this!. whoisdoctorwho.co.uk. Retrieved on 24 July 2013.
- Support & FAQs. Geocomtex website. Archived from the original on 26 September 2012. Retrieved on 24 July 2013.
- The Monster Files: The Trickster's Brigade. BBC - Doctor Who. Retrieved on 24 July 2013.