Preheat oven to 350 degrees.
Using a basting brush, lightly coat each cavity of 24 standard-sized muffin cups with melted butter. Gently place a wonton wrapper in each cavity, and using your fingers, evenly press the wonton wrapper around the muffin tin. Brush the topside of the wonton wrapper with melted butter.
Bake the wonton wrappers for 8-9 minutes, rotating the pan half way through, until they are light brown.
In a large mixing bowl, add the softened cream cheese. Using a hand or stand mixer, whip the cream cheese until light and airy. To the same bowl, add the Parmesan cheese, Swiss cheese, Worcestershire sauce, mayo and garlic. Continue mixing until well combined. Using a rubber spatula, gently fold in the shrimp and most of the green onion.
Using a cookie scoop or a spoon, divide the filling mixture into each of the wonton wrappers.
Bake for an additional 15 minutes. During the last 1-2 minutes, broil the wontons to brown the top layer of cheese. While broiling, do not walk-away! They can go from browned to burned very quickly.
Sprinkle reserved green onion on top of the wontons. Serve warm.