The premise for the sketch is a
BBC current affairs documentary programme, inexplicably titled
Ethel the Frog, retrospectively covering the exploits of the brothers Doug and Dinsdale Piranha. We learn through the mockumentary that Dinsdale and Doug were born "on probation" in the slums of London, with their father, Arthur Piranha, employed as a scrap‐metal dealer and TV quizmaster. The brothers are reported to intimidate their victims through 'violence and sarcasm'. Through a series of interviews with their victims, we find out that Dinsdale has a peculiar habit of nailing his foes' heads to the floor, while Doug is reported to be more vicious by assailing his enemies with
sarcasm: "He knew all the tricks,
dramatic irony,
metaphor,
bathos,
puns,
parody,
litotes and...
satire". One of those interviewed, the stereotypical Italian mobster and recurring Python character Luigi Vercotti, says he has "seen grown men pull off their own heads rather than face Doug". We are also told by another interviewee, a drag queen girlfriend, that Dinsdale is afraid of "Spiny Norman", a gigantic imaginary
hedgehog whose reported size varies on the basis of his mood. The threat of Norman has affected Dinsdale so severely that it leads him to launch a nuclear attack on an aircraft hangar, where Norman was thought to have resided, at
Luton Airfield on 22 February 1966, attracting the attention of the authorities ("Even the police began to sit up and take notice.") and causing a trans-Atlantic pursuit led by Police Superintendent Harry "Snapper" Organs of Q Division. At the end of the sketch, which also ends the episode, the creature is revealed as being real and appearing in an animated form bellowing "Dinsdale" beside various English landmarks as the credits roll. ==Album and book==