It's a clue type rarely seen outside Azed (and Azed competition clues) these days, although it dates back to the 1940s. Its introduction is credited to Afrit (AF Ritchie), and it was at one time referred to as a 'quarrelsome whale' type, the reference being to Ritchie's clue "You could make this whale seem quarrelsome, but hold it up by its tail and it begins to laugh (7)". The part following the comma is superfluous, reflecting the taste of the day for clues that ran to considerable length, but the first seven words represent a composite anagram (Azed's term for such a clue) which would be acceptable today. Colin Dexter's classic Azed comp winner "It's this Littlewoods could make you (8)" is constructed on similar lines, but is a 'comp anag &lit', with the whole clue serving as the definition.