Bi-generation
From Tardis Wiki, the free Doctor Who reference
Bigeneration was a variant of regeneration which the Doctor believed to be a myth. However, the Fourteenth Doctor experienced a bigeneration after being gravely wounded by a Galvanic Beam. This resulted in him continuing to exist as an incarnation distinct from the newly created Fifteenth Doctor. The process was assisted by Donna Noble and Melanie Bush who each grabbed and pulled the Doctor's arms to separate the two incarnations who both remembered their whole lifetime prior to the bigeneration. (TV: The Giggle [+]Loading...["The Giggle (TV story)"])