Preheat oven to 375 degrees. Lightly grease baking dish with non stick cooking spray and set aside.
Remove stems from mushrooms and wipe caps with damp cloth to remove any dirt. Place into baking dish.
In a small bowl, stir cream cheese to soften. Pour in parmesan cheese, taco seasoning, green onion, 3/4 cup cheddar cheese, salt and pepper. Spoon filling into cleaned mushrooms. Pour enchilada sauce over top. Sprinkle with remaining 1/4 cup cheddar cheese. Bake 20 minutes until browned and bubbly. Serve hot.