VIDEO: David Tennant And Matt Smith On Regeneration

"You wouldn't know about this yet, young man, but let me tell you..."

David Tennant and Matt Smith talk about regeneration and leaving Doctor Who in a new video clip released tonight by BBC America. In tongue-in-cheek fashion, David, who left the show on January 1st 2010, talks Matt through what he can expect following his own departure on Christmas Day.

Watch the video here:

Watch Matt's last hour as the Doctor in the 2013 Christmas Special, The Time of The Doctor, on Christmas Day on BBC America at 9pm/8c and on BBC One at 7.30pm GMT.