Either your song or your special cupcake has had an effect on the big doggy. He has fallen asleep leaving the gate wide open for you. You try to suppress the overwhelming urge to pet and/or poke the sleeping monstrosity. As you draw closer, you find a pair of water wings at the entrance to the beast’s cave. Why they are there and where they had come from are beyond you, but finders keepers!
(you may add Water Wings to your inventory, but remember you can only have five items at a time. If you have five items, discard one before adding another.)