作詞：   作曲： Knock knock, trick or treat? Who are you? I’m a ghost. I’m a little ghost. Knock knock, trick or treat? Who are you? I’m a ghost. I’m a little ghost. Knock knock, trick or treat? Who are you? I’m a cowboy. I’m a little cowboy. Knock knock, trick or treat? Who are you? I’m a cowboy. I’m a little cowboy. Knock knock, trick or treat? Who are you? I’m a witch. I’m a little witch. Knock knock, trick or treat? Who are you? I’m a witch. I’m a little witch. Knock knock, trick or treat? Who are you? I’m a monster. I’m a little monster. Knock knock, trick or treat? Who are you? I’m a monster. I’m a little monster. Knock knock, trick or treat? Who are you? I’m a ballerina. A little ballerina. Knock knock, trick or treat? Who are you? I’m a ballerina. A little ballerina. Knock knock, trick or treat? Who are you? I’m a pirate. I’m a little pirate. Knock knock, trick or treat? Who are you? I’m a pirate. I’m a little pirate. Knock knock, trick or treat? Happy Halloween. Happy Halloween. Knock knock, trick or treat? Happy Halloween. Happy Halloween.