Aagh ! 'Tis a fun thing that I first encountered in Wanchai,Hong Kong !! Basically, it is a childish toy (so therefore beloved of Jolly Jack ) which when shaken or struck against something (usually someone's head !) emits a very silly squeaky noise ! This can seem to be much funnier than it actually is after 6 or 7 pints of San Miguel or Tiger ! --- I regularly use mine when we do our version of "Those Were The Days" as per Mary Hopkins ; immediately after Karen (Wild Flying Dove) has sung the line " Once again There Came Familiar Laughter" or whatever ( I forget ), I administer a brief but very un-subtle SH solo, usually to the audiance's amusement.