Comfort comes in many shapes and sizes, but the Evie mule makes it oh-so stylish. This square-toe slip-on keeps it carefree with a flexible sole and sleek design. From Katy Perry. Modern Closed Toe Slides For Spring, Sleek Synthetic Slip-on Mules, Modern Flat Heel Slip-ons For Spring, Modern Slip-on Flats For Spring, Modern Slip-on Mules For Spring, Modern Flat Heel Slippers For Spring, Modern Flat Slippers For Spring, Chic Formal Slippers For Spring, Chic Slip-on Square Toe Flats