Glass avatars

Glass avatars (aka glass people) were avatars for the Testimony Foundation. In the final moment before a human being’s death, its consciousness would be preserved inside a glass avatar.
Podcast N144 Twice Upon A Time — The 2017 Christmas Special (re-review) > > > > > > >

Glass Avatars from the future don’t care about Data Privacy Agreements while the first and then-latest Doctor do Timelord Kegels to keep their respective regeneration at bay
Podcast B041 Twice Upon A Time – The 2017 Christmas Special > > > > > > >

Two doctors refuse to regenerate, then get into some scraps, then regenerate after all. It’s pretty great.