COOK vegetables as directed on package. Meanwhile, brown meat in large skillet; drain. Stir in gravy; simmer until heated through, stirring occasionally.
MICROWAVE cream cheese and 1/4 cup milk in medium microwaveable bowl on HIGH 30 sec.; beat with whisk until smooth. Gradually whisk in remaining milk and water. Microwave 2-1/2 min. or until hot, stirring after each minute. Stir in potato flakes and Parmesan until well blended. Spoon into resealable plastic bag; cut 1 corner from bottom of bag.
REMOVE 12 peas from mixed vegetables; stir remaining vegetables into meat mixture. Squeeze potato mixture into 6 mounds on meat mixture to resemble ghosts. Add 2 of the reserved peas to each for the eyes.