Did you get your dragon before or after you notice the goal pop-up ?
I have noticed that there is always some delay between the end of the Baron's tent season and the next one. During this time, some random items pop up in the tent (from a previous season) and the new season actually starts once you receive the new pop-up. This time though, I saw the "whose challenge is it anyway" pop-up (with the 0/4 counter) but I didn't see any flash screen announcing what items would drop eventually during the new season (sadly).
And usually the number of items is no more than 12. Therefore I suspect that the dragon might not be included in the current season... :/
Nevertheless, I got my lady bug faerie earlier and my goal is still in my book... (1/4) fyi