Twelfth Doctor (The Curse of Fatal Death)

The Twelfth Doctor came into being when the his previous incarnation regenerated after an eletrical mishap. As he said: "Three bodies wasted and all because I forgot to unplug."

He proved the shortest-lived, only living long enough to shut off a zegtronic energy generator before being hit by excess zegtronic energy and dying. He gave a final speech to Emma and the Master, asking them to "look after the universe for me - I've put a lot of work into it" and promised to explain later before dying, 'I'll... explain..." His foes the Daleks and the Master vowed to reform and live better lives life because of him, but then, unexpectedly, he regenerated into a new incarnation. (DW: The Curse of Fatal Death)