The item is the Baby Dragon, which we looked at alongside the Griffin (and other animals) on the 16th of this month. Now, the Baby Dragon is available to purchase from the game's store for 20 Farm Cash (or you can gift one to a friend if you feel so inclined). The Baby Dragon can be harvested from every two days.
As this item was released separately from the other Agricultural Alchemy items, its time limit in the store is also different from the rest of the theme. The original release of AA items will only be available for the next 8 days, but you can pick up this Baby Dragon for the next 18 days.
It's not very often that Zynga releases a new item outside of the regular update window (that being Tuesdays and Thursdays), and we'll be sure to let you know if and when they do it again.
For now, let us know what you think of this Baby Dragon in the comments. Will you purchase one for your farm?