Square Bubble

Have you ever wondered why bubbles always form as spheres? This is because the sphere shape can hold the largest volume of gas inside the bubble with the least amount of surface area. Try making a square bubble or even a pyramid bubble to test if different shapes can still create bubbles, even if they aren’t as efficient. What 3D shape would be the most difficult to create a bubble with, (i.e. what shape holds the least amount of volume with the largest amount of surface area)?