Frasier's Sister in Law 'Maris', Rumpole's wife (she who must be obeyed), Charlie from Charlie's Angels, etc All characters you either see very little of or not at all. Can you think of any others?
I don't remember Robin Masters too well but I recognise Norm's wife from Cheers. I just remembered Tom's owners (in the Tom & Jerry cartoons) were shown only from the knees down until relatively recently when they decided to give Tom and Jerry voices... Sacrilege!!
Columbo's wife - always mentioned but never seen, although I believe she eventually got her own 'spin-off' series. I seem to remember we actually got to see Rumpole's wife quite often and yes she was a bit of a dragon.
In Inspector Morse, Mrs Lewis, Sergeant Lewis's wife, appears infequently. Mind you she's always making demands on him to paint the spare bedroom and the like.
The mother of Mr Swainey (the next door neighbour) in "One Foot In The Grave". He used to wave to her from the garden, and you might have seen the curtains twitch, but that was all you got of her presence!