Pingos are a result of water - a lake for instance - placed on permafrost, where the top layer of water freezes. From the wind, which blows everything around, earth and plant growth gather on top of the frozen water/lake and makes a lid. The water between the permafrost and the ice-earth lid will at some point freeze, and in this process it will be pressed upward and a pingo is born.
Long before the freezer was invented Inuit people used pingos to store food in, just like as huge "walk in" freezer. They dug into the pingos and made chambers where they saved all the meat they collected from hunting. Here the meat could freeze and stay fresh until they needed it again, and at the same time it was protected from animals eating it.