This is the display/diorama you would have seen while McDonalds was having the Sonic 3 Happy Meal toy promotion. It's all cardboard and has 3D elements to better display the toys. It would likely have been in a plexiglass case. They went to quite a bit of detail here if you look closely at the layers. Hanging vines, diecut tree with monkey bot badnik, and ledge for Sonic to be on. The bottom says that you can win a copy of Sonic 3 if you enter the contest & has the copyright info. 

• Photo by SonicToast Photo by SonicToast
• Photos by Superhog Photos by Superhog
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This is the "spinning Knuckles" toy from the McDonald's Sonic 3 promotion, but this time with the bag it came in. Look at the poor art on the bag. Knuckles eyes are very vertical/strange & his head is very tall. They also add belts with buckles to his gloves like some of the other early art tried to do. The wheels under this toy drive a gear that makes Knuckles whirl around as you push it. 

Here's a better look at the Twirling McDonalds Knuckles rolling toy from above. With this turn-around you can see how he looks a little better than the awful art on the bag, but is still somewhat based on it. When you push this along a surface, he will twirl around in his gray dust cloud. This was a 1994 item.