WoW concurrs with "frogface". The subtitles which are (or at least, were) normally taken from the script, updated with ad libs, charmingly start the scene with "(Foggy muttering angrily)" then "(Cursing indistinctly)", but at the crucial moment "frogface" is used, but then, it's not very likely that anything much stronger would be written.
Resurrecting the earlier question of the proprietor's name above the café door, I'm rewatching all episodes from the pilot, up to the end of series 8 and haven't found anything. When I get to the very end, I suppose I'll just have to start at the beginning again. Ho hum.
I've often wondered if the café front was sometimes built be the scenery dept. They are so good it can be impossible to tell - there are relatively few shots through the door, though that is probably because of lighting problems (e.g. colour temperature). I'm more confident that Auntie W's shop front is built for the occasion. Perhaps someone knows better.
TTFN, WoW
P.S. does my nom-de-net of Wrinkled now seem out of place following the sad loss of Nora?