McDonalds did several Sonic Happy Meal promotions. Sonic 3 was their first. It included 4 toys that each did something different. (Gear needs a picture of the Knuckles one) Later, they switched to much more successful LCD games, and even went International.

The Sonic is a rolling toy, which pops off the base when you push the button. It is spring-loaded, and the base is meant to look like flames. The actual Sonic is somewhat goofy looking.

And there is Robotnik. You wind up his Egg-O-Matic, and it rolls along. There is a bead in the front that won't let him fall off edges. This is notorious for not working very well. Note the use of Eggman stock art that does not match the toy.

Tails is a Pull -n- go helicopter. Fit the white thing to the base, pull the cord, and it spins his helicopter-ring tails. This one breaks easily. If you're going to buy make sure that you're getting a working one.

Knuckles is a simple rolling toy. When you push his cloud along, he twirls in the center. No one's sure why though, as he didn't really twirl in any of the games, but oh well, at least he works well.

The poster seen in the cover image is what  was used in stores to announce the toys. The art is surpisingly accurate to the toys themselves (meaning it doesn't look very great) but it does manage to help the Tails try to look normal.

• Mind in Package photo discovered by SonicBoy19 Mind in Package photo discovered by SonicBoy19
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As you remember, McDonalds Sonic 3 promotion from FastFood 1, here's a look at what you would get MIP. Each toy was enclosed in a clear bag with a paper card. The card had activities (seen) such as a maze, plus some Sonic graphics & instructions for your item.