Sonic Back Pack Hangers!
Back Pack Hangers are usually larger keychains or keychain-type items that are too big for their intended purpose. So, hanging them on a backpack where they wouldn't fit into a purse or pocket like a proper keychain is the solution. Here, you can see the retail display dispenser stand for this latest round of them in 2020. They are (sadly) blind packed and there are 11 different ones to try and collect.
The back of the package shows you the characters you can get, with of course a couple of different ones for Sonic. They're all classic designs (so, not that many characters to make anyway) and the items are actual 3D little figures with plastic wing ring shaped clip tops. But, do be warned that BPH like these need to be sturdier than normal items because they are on the outside the whole time---yet they've chosen plastic lead loops for the tops so that's not a great idea. 

Here is the factory photo for these hangers, but, they've made a couple of mistakes for it. They've got Metal Sonic facing backward only, and then there are only 7 of the 11 different ones shown here. They've left Tails out completely, which is no good. What is good though, is the metallic paint for Metal Sonic is nice looking and so is classic Amy. Her pose is cute and her details are all in fine form. It's a nice little figure of her. Eggman is decent too, as are the chosen poses for Sonic & Knuckles. If these are reasonably priced, they'd be a good set to try and get--just rather too bad they're blindbagged. If photos of the other figures turn up, they will be added to the entry.