Kaczka and other 65,000 icons from Icons8 icon pack follow the visual guidelines of the operating systems: Windows, iOS, Android KitKat, and Material. PNG format is free up to 100x100 px. Icons are availble for download in PNG and vector (SVG, PDF, EPS, and more).
It's a logo of a duck. The body of the duck is made up of two "S" shaped lines with the head on top. There is a beak and a dot for an eye. The duck is facing to the right and has a line beneath it to depict the feet.