PLACE drink mix in large bowl. Add hot water; stir until drink mix is completely dissolved. Add cream cheese; beat with electric mixer on medium speed until well blended. Gently stir in whipped topping with wire whisk. Remove 1/2 tsp. of the cream cheese mixture for later use; set remaining cream cheese mixture aside.

CRUSH 3 of the cookies; place cookie crumbs in shallow dish. Set aside. Cut cake lengthwise in half. Frost cake top with some of the remaining cream cheese mixture. Dip in cookie crumbs until evenly coated; set aside. Place cake bottom on serving platter; frost top and sides with some of the remaining cream cheese mixture. Place cake top next to cake bottom to resemble coffin lid. Frost sides and cut side of cake top with remaining cream cheese mixture.

PLACE remaining cookie in center of cake bottom to resemble a body. Line up two rows of 3 mini marshmallows each at bottom of "body" to resemble legs. Place 2 miniature marshmallows on sides of "body" to resemble arms. Place large marshmallow at top of "body" to resemble head. Using reserved 1/2 tsp. cream cheese mixture, attach 2 miniature marshmallows to sides of "head" to resemble ears. Use decorating gel to draw mouth and eyes. Top cake with fruit snacks.