This surreal sketch closes out episode 7, "You're No Fun Anymore" (first season, airdate 11/30/69) of Monty Python's Flying Circus. Any reference on channel to blancmanges, playing tennis or otherwise, is usually part of a bonmotoring session, but TheLarch and I will sometimes use references from the sketch as a form of greeting, e.g. "TheLarch turns into a blancmange and serves an ace to Spup", "Spup chases TheLarch off the Wimbledon court with a spoon and fork"
Ah, but what is a blancmange, you ask? In French, "blancmange" literally means "white food" and it is an opaque, white, cooked pudding flavoured with almonds and thickened with cornstarch. It's a very old dish, dating back to at least Victorian England, and originally it was a savoury dish made with ground chicken. Nowadays it's more likely to be sweetened and served as a dessert. Blancmange is also the name of an eclectic 80s synthpop duo.