Not really Mousse, but a great way to fake it.
1 3/4 c. skim milk
1 pkg. instant chocolate fudge pudding mix
1 8 oz. container non-dairy whipped topping, thawed
Pour the milk into a large bowl and add the pudding mix. Beat on the lowest speed of a mixer for about 3 minutes. Carefully fold in the thawed whipped topping until the color of the mixture is even. Spoon into dessert glasses and chill for at least 20 minutes before serving. Serves 4.