The Doctor Who 60th anniversary specials feature many happy returns, but the greatest gift Russel T Davies gave fans and the cast was Bernard Cribbins. The actor -- who was 93 when his scenes were filmed and who passed soon after -- felt it was a gift to be asked to work again. The fans, who love his character Wilfred Mott also get to see the actor in action one more time. While a handful of scenes doesn't feel like enough, that's only because Cribbins was such a brilliant actor. While "Wild Blue Yonder" is the first time Doctor Who fans see Wilfred, it's not the first time he's mentioned. There's a gag in the first episode that hits a little harder now that Cribbins is actually gone.
Source：https://www.cbr.com/doctor-who-bernard-cribbins-return-gift/
