Which ingredient is used in both a Hairy Navel and a Fuzzy Navel?

The ingredient that is used in both a Hairy Navel and a Fuzzy Navel is peach schnapps. This liqueur contributes a sweet and fruity flavor that is characteristic of these cocktails. In a Fuzzy Navel, peach schnapps is combined with orange juice to create a refreshing drink. The Hairy Navel adds vodka to this mix, enhancing the alcoholic content while still retaining the peach schnapps flavor.

Peach schnapps is integral to both recipes; without it, the essence of these cocktails would significantly alter. Other ingredients like vodka, cranberry juice, and pineapple juice are not fundamental to both drinks, which makes peach schnapps the clear connecting ingredient.