Groupon offers the iHip Erasable Doodle Headphones in four colors for $19.99 with free shipping. That's $20 off list and the lowest total price we could find for these headphones. They feature side panels for doodling, noise-isolating design, padded headband, kid-friendly volume of 85dB, and erasable markers. Deal ends July 25 at 12:59 am ET.