Combine frozen banana, frozen mango, milk, peanut butter, and spirulina powder in a blender.
Blend until smooth and creamy, adding a little more milk if needed to reach desired consistency.
Pour the smoothie into a bowl.
Decorate the top to create a spooky Halloween design. For example, use banana slices for ghost shapes, blueberries for eyes, and chia seeds for spider webs.
Notes
Adjust the amount of milk to achieve your preferred smoothie thickness.
Feel free to experiment with different fruits and colors for your smoothie base.
Get creative with your toppings to make your Halloween design unique.