After you get the dragon, go flying to the bottom right of the map (go to the left of Jade's Magic Emporium). When you come to a winding river, kill off the Blackwings flying around, then land on the lowest part of the ground. Get off the dragon and you should see a small cave in the wall. Go into the cave and you will see a MASSIVE chicken. Kill it (be careful its pretty powerful, magic works best) and it will drop a golden egg. This will give you a tasty 1000 gold!