You can find a thread in Trading (in the Site Discussion category) area called "The Giving Tree". Ask to be put on the list for whatever rare dragon you're looking for. If someone's kind enough, they'll gift you an egg. There are other threads that allow you to 'work' (catching and cashing in commons) for rare dragons, like Clear The AP, So You Want A Silver Egg, Cave Plumbers.;
Go to the forums.
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