Plippy = the 'Pl' from Plastic + the 'ippy' from Hippy.
Plastic Hippy = Plippy (plural = Plippies)
The word Plippy came to me one day while I was standing in a queue for an ATM. There were 2 so-called 'Hippies' standing in front of me; you know, the ones with long dreadlocks, have dogs as friends by default, and are usually either smoking a joint or drinking a can of beer (if not both). But these 2 were different; sure they had the hair, the dogs and the beers, but they were also wearing designer clothes and glasses, and took out €300 from the ATM! Modern-day hippies with plastic cards = Plippies