This is a foil enhanced Sonic backpack. It's from a series of school items released by the same company "Animations". They have a messenger bag & other items all with this same shiny blue somewhat iridescent foil as the big design enhancing theme.

The backpack is pretty fun, with big glossy thick plastic modern 'thumbs up' Sonic design. The back is plain black, as are the straps, but the blue edge is decorated with lots of modern Sonic line arts. It has 2 side mesh pockets & 2 main zipper areas. The edge-rim bead is also that foil stuff. Notice the modern logo at the bottom of the bag as well. The foil effect is sort of hard to capture on camera because it's so bright/reflective.
This bag was bought at retail in the USA...but at which store? Could have been Walmart or Toys R Us, but it is confirmed that Animations products (so, likely their other Sonic bags too) DID make it to brick/mortar retail. This bag is likely to be somewhat uncommon.