These came out around the time of Sonic 2. They are also probably the most widely-distributed plushes of any age. Almost anyone could buy them if they wanted to. They were avialable in Babbages, electronics stores and toy stores. (That is a floppy disk in the 2nd picture, so you can see the size--it is from my collection)
Notice the Tails. He isn't really orange. It is actually an annoying brown color. Archie comics had the same problem, making him brown like a normal "Earth Fox" because they could not grasp the concept that he too, is an unnatural color.

Look at the last 2 images in the gallary to read 2 nice little stories. These tags were used with a few different plushes in the era. These 'stories' are probably on the box-backs of the above dolls. (Complete with grammar errors..."Lot's Done"?)

The main benefit to the above dolls is that they were produced for quite an extended amount of time. Because of that, there weren't really any big sell outs, price crunches or monsterous Ebay demands. It should still be easy for you to aquire one of these guys. A Classic doll will do your collection some good. Both of these guys are from Caltoy, and are around 13 inches high.

Tag image sizes kept large so you can read them right off the picture. Sonic's tag is dated 1993, and Tails' is dated 1994.

• Sonic old plush turnaround Sonic old plush turnaround
• Tails old plush turnaround Tails old plush turnaround
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Here they are with turn-arounds for their box. Tails is quite sadly...ugly, with a huge nose and off-color. The giant-ness of the nose may have been fixed in later dolls. Sonic always remained fairly solid and cute. 

• 1993 plush owned by BruhSonicTehHedgie 1993 plush owned by BruhSonicTehHedgie
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One of the first things to go off of a plush is the paper tag. After all, it doesn't have the durability of fabric. So, here's a nice look at Caltoy's famous Sonic's paper tag. It was a fold-over with a blurb inside so now you can finally know what it says. "Hi my name is Sonic the Hedgehog, I'm the blue superhero hedgehog with an attitude that's been providing hours of enjoyment to video-gamers world0wide. It's no surprise that kids love me cause I'm Way Past Cool! But I got a problem and I need you help. I like to do everything fast. With my Super Sonic Spin, I can get lots done but I don't have the time to hang around this place. T hat's where you come in and how I get out -- take me with you! It will be just you and me beginning a whole new adventure together. And I promise you it will be fantastic fun or my name isn't...Sonic the Hedgehog!

You can also see the 1993 Sega copyright down there to put a concrete date on Caltoy.