Extragalactic Blancmange puddings feature prominently in the last four linked sketches of the TV show Monty Python's Flying Circus in the seventh episode, You're No Fun Anymore (Science Fiction Sketch; Man Turns Into Scotsman; Police station; Blancmanges Playing Tennis). Their fundamental absurdist humour is to upturn the usual relationship of people eating food, into food eating people.
A table-size sentient Blancmange from planet Skyron of the Andromeda Galaxy turns the tables by eating people, especially now-historic players of tennis. Alien Blancmange(s) also have the power to instantly turn 48 million English citizens into northward-marching Scots. Chief Scientist Charles, his mistreated bimbo girlfriend, and a police detective eventually deduce that this bizarre cultural conversion and player consumption is an effort to depopulate England and win the Wimbledon tennis championships. The core theory here is that if everyone in England is turned into Scotspeople, they are sure to lose the tennis match, since (according to the characters) Scots are terrible at tennis. What the Blancmanges stand to gain by winning at Wimbledon is never brought up.
The Blancmange(s) from space eat 1970s tennis stars. Then, a single tennis-playing Blancmange is thwarted when it is chased and eaten by a couple armed with forks, spoons, and napkins. The couple, Mr and Mrs Samuel Brainsample, were snubbed as boring in the first scene, but they too just happen to be from the Blancmange(s)' home planet of Skyron. With all the famous players and the Blancmange eaten, the only remaining tennis player is kilt salesman Angus Podgorny. Podgorny seems strangely cheerful for having watched his wife being eaten a few scenes earlier. The wrapup sports announcer (John Cleese) narrates the unlikely TV spectacle of a Scotsman winning Wimbledon after playing against himself — running back and forth around the net — for 15 years, we are told. (Technically, though, he didn't win the match, as the "winning" shot — a smash of a lob that took several seconds to come down — landed about a foot beyond the end line.)
Multiple Blancmange sightings are mentioned, but only one is seen and eaten in the final sketch. The Monty Python Blancmange looks more like a round coffee table in a white fabric tent than a gelatinous pudding.
Blancmanges are commonplace in the UK, and as such these Monty Python sketches didn't explain what they were. The sketches do not show a real blancmange, so when the sketches arrived in the USA on public television, they baffled most viewers. That food is generally unfamiliar to Americans, and the intended food humour is typically incomprehensible in the U.S. The incomprehensibility enhances the Pythonesque reputation for creative absurdity, but the people-eating scenes (off camera with slurping noises) become more horrific than the writers intended. This is yet another variation on the theme of cannibalism from which Monty Python periodically extracts edgy humour.
The word is typically unspellable by just listening to it in the USA. Fortunately "Blancmange" is spelled out during the display of a tennis score during the sketch and can be looked up by those baffled.