Yelled as a preface to fourteen 11-year-old boys wrestling a passer-by to the floor, and stuffing their mouth full of grass. Presumably, because it was an experiment, teachers were loath to interfere, in case they rendered the results useless.
The practice of using a black fineline pen to give the players on Panini football stickers giant afros. Each afro should be bigger than the previous one - students may use an extra sheet of paper if necessary. It is only polite to shout "EXTENDER HEAD!" when you are drawing.
When playing Lucozade (qv), any disabled child with an external bladder may find that they can hit the ceiling by punching their bag. This feat, impossible for those with internal bladders, will afford the window-licker (qv) with a rare moment of kudos.