Posted by Mama Mia on April 24, 2003
The listing in the Mondegreen section of the Phrase Finder does not give a source for the mis-hearing of the line from Bohemian Rhapsody by Queen.
Could it come from the cover version of B.R. done by the Young Ones? They certainly use the line "Beelzebub has a devil for a sideboard" instead of the correct lyric.
Of course, they may just have been repeating a popular mishearing, but I am not enough of a Queen fan to know....