Trace your hand and wrist onto a piece of waxed paper; flip over and set aside.
In a large microwave-safe bowl, microwave white candy coating on high for 1 minute. Add 3 cups marshmallows. Cook 20-30 seconds longer or until melted; stir until smooth. Stir in cereal.
Working quickly with buttered hands, shape cereal mixture on waxed paper to form a hand; cool slightly. Mold hand portion over an inverted glass bowl; cool until set.
Cut a small hole in the corner of a pastry or plastic bag; insert round tip #4. In a microwave, melt chocolate candy coating; stir until smooth. Fill bag. Pipe coating along the long edge of a cracker; attach, side-by-side, to edge of a second cracker to form one box panel. Repeat with remaining crackers, making five more panels.
To assemble box, place one panel on a serving platter. Pipe coating along perimeter of entire panel. Pipe coating along one edge of a second panel; attach to a third panel, forming a right angle. Pipe coating along inside edge for added stability; secure to bottom panel. Repeat with two additional panels. Refrigerate until set.
Place a small bowl, upside down, in box; add remaining marshmallows. Transfer hand to box, resting base of hand on bowl for support. Reheat candy coating if necessary. Attach one edge of the remaining panel to box, forming lid. Let stand until set.Place remaining marshmallows in box; add hand. Reheat candy coating if necessary. Attach one edge of the remaining panel to box, forming lid. Let stand until set.