Selling a Dragon is something we want to do from time to time and by doing this, we will get some Gold in return.
However, if you are a new player, you will need to collect more Dragons before the "Sell" button appears.

To sell a dragon, follow the steps below:

1) Tap on the habitat where the Dragon you want to sell is located
2) On the list of Dragons that pop up, select the Dragon.
3) On this screen, you will find the "Sell" button
4) A confirmation pop up will appear to make sure you are making the right decision.