1. Preheat oven to 425°F. In a bowl, mix crushed oreo cookie halves and butter. Pat into bottom and sides of 10 inch pie dish. Bake in oven for 5 to 10 minutes; remove from oven and cool completely. Once cooled, place in freezer to chill.
2. In saucepan, melt marshmallows in milk over medium heat. Remove from heat and cool. Add creme de menthe and creme de cacao, and mix well. Add a drop or two of green food dye if desired. Fold in whipped cream. Pour into chilled pie shell.
3. Freeze for 3 or 4 hours.