Monster Jam Backpack for Boys - Bundle with 16" Grave Digger School Bag, Water Bottle, Tattoos, & More | Monster Jam School Backpack for Boys Set. This Monster Jam school bag set includes a 16" blue backpack with adjustable straps, front pocket, and a top loop for hanging. Backpack features artwork of Monster Jam truck Grave Digger. This Monster Jam backpack for kids is the perfect size to carry your notebooks, binders, pens, pencils, and any other superhero school supplies. Take this Monster Jam bag with you wherever you go! Officially licensed Monster Jam backpack set includes racecar temporary tattoos, a Beach Kids water bottle and a Beach Kids video game door hanger, making it a perfect set for back to school! WARNING: CHOKING HAZARD—Small parts. Not for children under 3 yrs.