(Thanks to 1candy0 for the images)
To start the scavenger hunt, go to Rockhopper’s ship and click the notice:
Go to the iceberg and feed the animal in the water with fish until it spits out the telescope.
Go to the dock and rebuild the ship. You will get the tropical feather if you complete it.
Go to the forest and climb up the ladder to the Tree House. Play the drums to sound like the birds. Once done, an egg will fall. Click it to get the old key and the map. After, go to the cove.
Go to the “X” and use your jackhammer to dig into the ground. If you dig deep enough you will find the Cream Soda!
You will get a hat as a reward for finding the cream soda! You have also earned pins as you went through the Scavenger Hunt. Congratulations!
-Dino Boy7
(Credit to ClubPenguinCP)