A pookie, also referred to as a 'pookie-head', is someone who takes MDMA, also known as 'rolls' or 'ecstacy', in excessive amounts. Pookies incur a large spectrum of symptoms, including incessant talk of
the last time they 'rolled', a
psychological addiction to MDMA itself, showing off the fact that they take MDMA by wearing pacifiers, etc.
Eventually, a severe pookie seems to be out of touch with the world in terms of reality and happiness. They seem drawn out, only awaiting the next time they take Ecstacy.