It only appears on reels 2, 3 and 4. You may also be entitled to a jackpot when Fu Bat appears. It depends on the number of golden symbols you play at the time.
This is where the 'All Up' betting format comes in. For extra points, you can turn more symbols into gold. For example, an extra golden icon takes 8 credits, but 5 golden symbols will give you 88 credits. The more gold symbols you pay, the more progress you can unlock.