In case you need something to occupy you as you watch Twice Upon a Time, I’ve produced a quick bingo card (left), letting you tick off all those mentions/ cameo appearances. I’ve not seen the preview, so it’s all guesswork. I’ll let you know how well I did next week! [And here’s a link to the full-size version.]
As an aside, Jenna Coleman was on the Chris Evans show on BBC Radio 2 this morning; I caught some of it, no mention of any cameo, just her role as Queen Victoria later on Christmas Day. Surely she will appear? Perhaps even Nardole or River? Not long to wait now!