1 gallon vanilla ice cream, softened
1 gallon milk
4 3/4 cups dark rum
4 3/4 cups coffee-flavored liqueur (such as Kahlua®)
4 3/4 cups vodka
1 pinch ground nutmeg, or to taste (optional)
Whisk vanilla ice cream, milk, rum, coffee liqueur, and vodka in a large punch bowl until frothy and liquid; garnish with nutmeg. Ladle into punch mugs.