Final answer:
A Chiffon pie has a fluffy filling made from gelatin and fruit and is known for its light, airy, mousse-like texture.
Step-by-step explanation:
The type of pie with a fluffy filling made from gelatin and fruit is a Chiffon pie. This pie is known for its light, airy texture that comes from the incorporation of beaten egg whites or whipped cream into the gelatin-based mixture. Unlike cream pies which are generally denser and cream-based, chiffon pies have a mousse-like consistency that can incorporate a variety of flavors like lemon, pumpkin, or berry.