In a large bowl, beat pudding mix and eggnog with an electric hand mixer or stand mixer with fitted paddle attachment until smooth and slightly thickened, about 2 minutes.
Gently fold in whipped topping and nutmeg. Pour evenly into prepared pie crust.
Cover and refrigerate for at least four hours, or until firm.
When ready to serve, garnish with additional whipped topping and a dusting of nutmeg, if desired.
If you want to get extra indulgent, you could serve this with some eggnog ice cream right on top of the pie!