1 (20 oz.) can crushed pineapple, undrained
1 (3 oz.) pkg. instant pistachio pudding
1 (8 oz.) carton Cool Whip
1 graham cracker crust

Mix pineapple and instant pudding, fold in Cool Whip. Pour into graham crust and refrigerate. Before serving, more Cool Whip can be added on top of pie, if desired.