If you want this in sticker form, feel free to print it yourself--consider the art licensed CC-BY.
Otherwise here is a link where someone else will print it and send it to you: https://teespring.com/push-pop-een#pid=663&cid=102920&sid=front
If you want #datastructures and/or #cats on your incarnate person, I put up a thing where you can order t-shirts in various shapes and sizes, including kids: https://teespring.com/push-pop-een-shirt