Combining stout-style beer and chocolate ice cream can make a boozy dessert drink that closely mimics the flavors of a root beer float, but because we hate to mess with a good thing too much ...
You can always spike a traditional root beer float with a shot or two of vodka, or you could completely elevate your ice cream float experience by replacing root beer with alcoholic beer.
who called any kind of soda suitable for adding milk or vanilla ice cream to a "cream soda." Considering the popularity of root beer floats, it seems that root beer could be considered a cream ...