This is how to unlock the new charakter Gains Boros (Secret Dragon Shrimp Character)
How to unlock
1. Choose any character and go to the bone zone
2. Run upwards past the Silver Ring
3. Search for the flower ring
4. Stay in the flower ring and wait for it to disappear (you will hear an unlocking sound)
5. You can now quit. You will find the Character in your selection screen
This is what the flower ring looks like
In my case it was here on the map (might vary in your game)