FtHoF sometimes yields a really slow cookie
Sometimes when I cast FtHoF a GC appears reeeeeeeeeeeeally slowly. When you click it, it only yields some amount of cookies, but has no further caption (like Lucky, Frenzy etc). What's the deal with these? Should you click them as soon as possible? As late as possible? How long will they stay? What's the yield? Does the height of the bank have any influence?