These PVCs were sold as a pair however
...they're re-issues from other sets. You can see the Tails in other photos here. Notice Sonic's error, he has blue arms. (Other similar PVCs have his arms down) 

In the gallary is a better look at the 'arms up' Sonic PVC above. As you can see with these photos, they had a decent grasp of what his spikes should look like, even at this early year. You can see the trademark on the back of the head, & it says "C Sega ents. ltd. 1992 Lic by CPL". Notice the paint scuffs; these reveal that he isn't solidly colored plastic like some figures are.