I enjoyed watching GREER GARSON as the mystery guest on a 1958 edition of WHAT’S MY LINE. (Available to view on YouTube.)
Greer was at the time appearing on Broadway in AUNTIE MAME and was outfitted as the character, with a long cigarette holder – Greer puffed away throughout her appearance.
She put on a wonderful deep,foreign accent and the panelists ( including ORSON WELLES) weren’t sure whether the guest was a man or woman!
And they never did identify her!
Greer took over from ROSALIND RUSSELL in “Auntie Mame” and appeared successfully for 6 months.
I love this picture of Greer from RANDOM HARVEST.