This is a package of Danimals Smoothies, which are probably some type of sorta-liquid fruit flavored yogurts for kids. They may or may not be an actual 'Sonic food' (is the smoothie themed for Sonic somehow?) but they sure are a Sonic promotional item that ON a food...so here it goes.
It has modern Sonic on half of the package and says "Unlock Sonic Rewards", but what does it mean? What are the prizes? You can write in if you know what this is about.