Referred to in popular
American sitcom Friends
, in which
in one episode Phoebe
and Joey concoct
an 'evil' plan to get Rachel and Ross back
together by setting them both up on terrible dates in the hope that
how right they are for one another or something.
But anyway, once they have formed
the plan Phoebe
points out that
this means they can do the plan laugh, which
is basically an evil laugh which follows
the creation of a good ol' fashioned evil plan. Usually used by villains such as Bond villains etc.
a bit like this, "Muahahahahahahahahahaaaaaaa"