Physiognomy
From Tardis Wiki, the free Doctor Who reference
When the Fourth Doctor first examined himself in the mirror after regenerating he noted that "as for the physiognomy... well nothing's perfect". (TV: Robot (part one) [+]Loading...{"part":"one","1":"Robot (TV story)"})
When the Eleven used the Crucible of Souls to grant all contemporary lifeforms in the universe the ability to regenerate, without end and without a need for change in physiognomy, he gave the Ravenous an endless supply of regeneration energy, on which to feed and multiply. (AUDIO: Day of the Master [+]Loading...["Day of the Master (audio story)"])