Saw this one a while ago on the net about a cargo plane doing the same route night after night and after while went in with approach of destination airport (around dusk) with :
XXX tower, guess who's coming ?
Each time the Tower asked him to identify himself clearly on the frequency instead of joking, never succeded...
until that day during winter period :
XXX approach, guess who's coming ?
Tower controller (turning off the runway lights, still no daylight)
Flight XXX, guess where we are now...
From that day, the story says that this cargo pilot always identified at contacting the tower
