Ninth Doctor

The Eighth Doctor regenerated into an individual who would logically have been called the Ninth Doctor after he broke his bones falling back into the Doctor's TARDIS from the eyrie on which he had activated the Moment, destroying the Time Lords and ending the Last Great Time War.

Once the regeneration died down, the Doctor, his thirst for life renewed despite the horrors he had witnessed, eagerly felt at his new face before exclaiming his first word: "Blimey!". (PROSE: Doctor Who and the Time War)

Behind the scenes
"…the Ninth Doctor here could also be interpreted as the Shalka Doctor or the Rowan Atkinson Doctor for the hat trick of alternative Ninth Doctors."
 * Although the specific mention of "ears" as the new Doctor is feeling his face suggests Christopher Eccleston's Ninth Doctor, Doctor Who and the Time War does not positively identify the Doctor into whom the Eighth Doctor turns. Echoing The Tomorrow Windows's in-universe confirmation that the Doctor would somehow have "three ninth incarnations", Russell T Davies answered affirmatively to a comment by a fan on the Instagram release of Doctor Who and the Time War suggesting that—

- (source)


 * This followed Davies' earlier comments that clarified Doctor Who and the Time War's position in relation to The Night of the Doctor as a "glimpse of parallel events" and his broader statement upon its release that "all Doctors exist [and] all stories are true".