Preheat oven to 350 degrees F. Coat a baking sheet with cooking spray.
In a small bowl, combine cheese spread and scallions. Spoon 1 teaspoon mixture into each phyllo shell and sprinkle evenly with Cheddar cheese. Place 1 shrimp, tail sticking out, in center of each filled shell.
Place shells on baking sheet and bake 10 to 12 minutes, or until filling is heated through and shells are golden. Serve immediately.