Dragonflies begin life in water as eggs then  hatching into larvae also known as nymphs. They crawl out of the water and the adult will emerge out of a crack in the back of the nymph.  This left behind nymph-skin is now referred to as an exuvia.  It feels like a crinkly piece of plastic when picked up. They can easily be found around the edge of ponds and lakes attached to vegetation, sticks and rocks.