Combine the mayonnaise, sour cream, and ranch seasoning mix in a small bowl. Stir until smooth and set the dip aside.

Cut the celery stalks in half lengthwise to form long strips for the skeleton spine and limbs. Slice the carrots into thin sticks for ribs and smaller bones.

Slice the cucumber into rounds and cut the red bell pepper into strips to use for additional bone shapes and joints.

Place the broccoli florets at the top of a large platter to create the skull shape. Add two cherry tomatoes for eyes.

Arrange the celery and carrot pieces down the center and sides of the platter to form the spine and rib cage. Fill in the rest of the skeleton outline with cucumber rounds and pepper strips.

Scatter the remaining cherry tomatoes around the platter as accents. Serve the ranch dip in a small bowl beside the finished skeleton.