I'm reminded of the spider egg decks in Hex, where there's all sorts of things that adds them to your opponent's deck. When one is drawn or milled from your opponent's deck, it immediately fires spawning a spider token creature for you and the opponent draws/mills again.
I think it's a neat idea, but the spiders only really work because it's a digital game and so you don't have to worry about the logistical problems or accidentally leaving cards in your opponent's deck between rounds of a tournament. Maybe in a alternate format like TD? I could see a campaign Jinteki card totally mining the crap out of the runner's deck with cards that pop them for net damage when drawn.