To prepare crust, combine crumbs, margarine, and sugar in a mixing bowl. Press mixture firmly in a 9" pie pan. Pour jello into a bowl. Add boiling water. Stir until disolved, about 2 minutes. Add ice cream to jello. Stir until ice cream is melted and mix is smooth. Place in refrigerator and chill until slightly thick, about 10 minutes. Remove from refrigerator and pour mix into pie crust. Put pie in refrigerator to chill until firm, about 2 hours. Take pie from refrigerator and make Jack-O-Lantern face on pie with candy corn and licorice. Decorate with whipped topping if desired.