Eggstatic Eggstravaganza Hat Adventure
New hat adventure.
Thankfully everyone should have this hat set, it is an existing one and only in the "rare" category.
Edit:
Rewards are all feathers except for beating round 1, just a chest. 10,000 feathers for finishing the challenge.
Took me about an hour to beat it. I got lucky with a couple of Mighty Eagles on rounds 5 and 7, but spells seemed to be very generous overall and none of the rounds are overly difficult.