Peel the clementines completely, ensuring all white pith is removed.
Slice the celery stalk into four 1-inch thin strips to serve as stems.
Insert one celery strip into the top center of each clementine to create the pumpkin look.
Peel the bananas and slice them in half crosswise.
Stand the banana halves upright on a flat surface with the curved tip pointing upward.
Press two mini chocolate chips into the upper third of each banana half to form eyes.
Press one standard chocolate chip below the eyes to create an open-mouthed ghost expression.
Arrange the fruit on a serving plate and serve immediately to prevent browning.