Time Beetle
The Time Beetle was an insectoid creature resembling a giant stag beetle that was capable of manipulating time. According to the Tenth Doctor, it was "one of the Trickster's Brigade". With the help of something to let it inside its victim's mind, such as a board game or fortune teller, it was attached to unsuspecting victims, after which it changed a key event in their lives. In most cases, this would have little impact; the victim's life would change and the universe would compensate. For important people, like Donna Noble, whole new parallel worlds could be created.
In a parallel world created by the Beetle, it existed in a state of flux, and could not be touched. Though it was invisible to humans, some sensitive individuals were able to see it, particularly as major timeline changes were coming to pass.
The Beetle could also be made visible using the technology of the Lodestone. Once it was removed from Donna and stripped of its hold on time, the Tenth Doctor was able to directly observe and interact with a Beetle's corpse.
One account identified the Time Beetle as a member of the Pantheon of Discord, (PROSE: Doctor Who: The Encyclopedia [+]Loading...{"page":"264","ed":"2011 reprint","1":"Doctor Who: The Encyclopedia (reference book)"}) which the Eleventh Doctor later corroborated. (PROSE: "Time for Friends!" [+]Part of Doctor, Doctor! 273, Loading...{"name":"\"dwa\"","page":"29","namedpart":"Time for Friends!","1":"Doctor, Doctor! (DWA 273 short story)"})
The Beetle specifically fed off the time energy created by disruptions in an individual's timeline; (PROSE: The Time Traveller's Almanac [+]Loading...{"chaptname":"Everything Changes","page":"132","chaptnum":"3","1":"The Time Traveller's Almanac (reference book)"}) indeed, Rose Tyler knew that the Beetle "[fed] off time, by changing time." (TV: Turn Left [+]Loading...["Turn Left (TV story)"])
History
The Time Beetle claimed other victims before Donna Noble, including a man who Torchwood had tasked with investigating the board game The Trickster's Brigade, which depicted the Beetle on its board and cards alongside the Trickster and the Graske. (WC: Monster File: The Trickster's Brigade [+]Loading...["Monster File: The Trickster's Brigade (webcast)","Monster File: The Trickster's Brigade"]) Before the Time Beetle attached itself to Donna, Lucius Petrus Dextrus prophesied to the "daughter of London" that "there is something on your back." (TV: The Fires of Pompeii [+]Loading...["The Fires of Pompeii (TV story)","The Fires of Pompeii"])
A Time Beetle attached itself to Donna Noble, (TV: Turn Left [+]Loading...["Turn Left (TV story)"], etc.) disrupting her timeline (PROSE: The Time Traveller's Almanac [+]Loading...{"chaptname":"Everything Changes","page":"132","chaptnum":"3","1":"The Time Traveller's Almanac (reference book)"}, The Visual Dictionary: Updated and Expanded [+]Loading...{"page":"41","1":"The Visual Dictionary: Updated and Expanded (reference book)"}) and creating a parallel world around her in which she never met the Tenth Doctor. This resulted in his death during the Racnoss incident, without her to stop him, and the subsequent deaths of Martha Jones, Sarah Jane Smith and the Torchwood Three team (apart from Jack Harkness, who became trapped instead).
The planet Earth, and Britain in particular, descended into chaos over the next two years in the aftermath of various alien attacks and catastrophes which the Doctor was meant to have stopped. Even the stars began going out, (TV: Turn Left [+]Loading...["Turn Left (TV story)","Turn Left"]) as Davros unleashed his Reality Bomb, uncontested. (TV: Journey's End [+]Loading...["Journey's End (TV story)","Journey's End"])
With Rose Tyler's help, Donna went back in time to the beginning of the new world and stopped herself from turning right, restoring events as they had been. At this point, the Time Beetle released itself from Donna's back, and died from the tremendous force. (TV: Turn Left [+]Loading...["Turn Left (TV story)","Turn Left"])
The Time Beetle was the subject of William's letter to Doctor Who Adventures: did the Beetle have any friends, such as a Time Worm or a Time Spider. The Eleventh Doctor responded, firstly clarifying the Beetle's association with the Pantheon of Discord before speculating about similar members, such as Time Worms, Space Parrots and Dimension-Jumping Cheese Weasels, given the Pantheon's love of chaos. He confessed that he would like to be friends with everyone, so long as they gave up their life of meddling with time. Furthermore, an image accompanying the Doctor's response showed the Time Beetle on the Doctor's back, although the exact nature of this was ambiguous. (PROSE: "Time for Friends!" [+]Part of Doctor, Doctor! 273, Loading...{"name":"\"dwa\"","page":"29","namedpart":"Time for Friends!","1":"Doctor, Doctor! (DWA 273 short story)"})
Behind the scenes
The Time Beetle, with its position on its host's back, was inspired by the Eight Legs of Metebelis III.[1]