Drizzle caramel syrup and chocolate syrup inside a martini glass. Arrange glasses on a tray; freeze until needed. Heat dark chocolate over medium-high heat until chocolate begins to melt, shaking the skillet occasionally; do not stir. When the chocolate begins to melt, reduce heat to medium-low. Immediately pour chocolate on foil and use a spoon to make a thin and even layer. With a knife draw out the bat silhouette and allow for it to set and harden. Combine ice cream, rum cream, caramel syrup, and chocolate syrup. Cover and blend until smooth. Pour mixture into martini glasses and top with the chocolate bats. Makes 4 servings.