Sonic the Hedgehog Backpack for Boys 4-6 - Bundle with 16" Sonic Backpack Plus Water Bottle, Stickers, More | Sonic Backpack Set. This Sonic backpack set includes a 16” backpack with adjustable shoulder straps, zip closure compartment, and top loop for hanging featuring colorful artwork of Sonic the Hedgehog. This Sonic backpack for kids contains plenty of room to carry school supplies, your water bottle, and any other small items you need to take to school or on the go. Show off your love of Sonic in style. This Sonic backpack bundle also includes a Beach Kids water bottle and Rex-Man stickers, making the perfect gift set for any Sonic or videogame fan. Officially licensed Sonic the Hedgehog backpack set is perfect for fans of all ages, boys and girls, alike. Set also includes a bonus Rex-Man door hanger.