The line comes from The Legend of Old Gregg, a 2005 episode of the British comedy series The Mighty Boosh on BBC Three. Old Gregg, played by Noel Fielding, is a lonely sea creature who confronts Howard Moon in a cave and proudly shows him his mangina. The scene became one of the show's most quoted moments, spreading through early YouTube clips, forums and quote pages. Its surreal humour helped it survive as a reaction sound long after the series ended.