I'm not from DECA, but did you click to cast a spell to bring the flying dragon down from the rooftop on the event island?

This would cost 12,000 magic and after 3 days put a Treebark Dragon egg in your gifts.

If it wasn't from a purchase in the game it could be good to contact DECA Support:

https://support.decagames.com/hc/en-us/requests/new

They will probably need your Park ID sent in the request to look into it.