Doctor Number 37: The Eleventh Doctor
Things get slightly less complicated with the Eleventh Doctor…well not really.
A robot/spaceship called the Teselecta was able to disguise itself as humanoids and at one point took on the form of the Doctor and seemingly started to regenerate. How far this process could proceed is unknown as the Teselecta was shot before the process could complete and left this fake Doctor supposedly completely dead. Either way, this was in no actual way a version of the Doctor.
The Eleventh Doctor would continue on until they became the Twelfth Doctor, although they didn’t expect to be able to regenerate. With the two Tenth Doctors and the War Doctor, it seemed as if the Eleventh Doctor expected their time as this incarnation to be their thirteenth and last life. This changed when the Time Lords granted a new cycle of lives to the Doctor which is an idea which had happened before with them granting the Master a new regeneration cycle during the Last Great Time War.
The story of the Timeless Children would seem to indicate that the Doctor always had the ability to regenerate an unlimited number of times anyway, so their granting the Doctor this new regeneration cycle may either have been smoke and mirrors to maintain the lie that the Doctor could only regenerate twelve times, or they themselves didn’t know the Doctor could regenerate indefinitely.
A third possibility is that the Time Lords were able to impose a twelve regeneration limit onto the Doctor at some point, although for the many lives covered in this theory to be able to work, we’ll have to go with the idea that the Doctor was able to regenerate an unlimited number of times as the Timeless Child story has introduced.
Doctor Number 37A: The Ganger Doctor
During the era of the Eleventh Doctor, he gets a Ganger (doppelgänger) version of himself which is a clone made of programmable living tissue. It was able to take on the appearance and memories of the Eleventh Doctor and was even able to produce the voices of previous regenerations of the Doctor. This version of the Doctor didn’t survive for long and as it was a clone that copied the DNA of the original but wasn’t actually part of the original, we’ll say this is a side note until more evidence comes to light that this was a full new incarnation of the Doctor.
Doctor Number 37B: The Dream Lord
Played by Toby Jones, the Dream Lord plagued The Doctor, Amy and Rory by putting them into scenarios where they couldn’t tell if they were awake or asleep. It would later be revealed that the Dream Lord was in fact part of the Doctor that manifested due to a psychic pollen they were exposed to. As this version of the Doctor didn’t have a true physical form we can view it as an extension of the Eleventh Doctor, although it may be possible for this version to return at some point and perhaps in a more tangible form.
Doctor Number 38: The Twelfth Doctor
The Twelfth Doctor is said to have been the first regeneration from a new cycle of thirteen lives, which after a period of fifty years of the show would allow it the potential of another fifty years before the writers would have to address this issue again. Of course, since this time, the Timeless Child storyline would mean that they never need to worry about regeneration limits ever again.
Also, as mentioned earlier, the Twelfth Doctor took his appearance based on his meeting of Caecilius in the Tenth Doctor story The Fires of Pompeii. This was explained as being that the Doctor subconsciously took this face to always remind himself to save people as he had done in Pompeii. Of course, the real reason for this is because Peter Capaldi played both parts, but this precedent does show that on some level, a Time Lord, or at least The Doctor can influence their appearance.
This idea may be relevant in explaining why the Shalka Doctor, and the second Curse of Fatal Death Doctors both resemble The Great Intelligence. In reality it is because all three were played by Richard E Grant, but in universe there could be a connection to why the Doctor would have chosen the face of an enemy for two of his own faces.
This may also go some way to explain how the Doctor was able to retain his appearance of the Tenth Doctor when syphoning excess regeneration energy into his extra hand. The syphoning of the energy may not have been enough to stop the change of appearance, but the desire to attempt to keep his current form may have also played a part in it.
