Vintage Sonic & Shadow Papercraft

I enjoy digging up older papercraft so people can continue to enjoy them. A recent find was these Sonic the Hedgehog and Shadow the Hedgehog paper models. Here is what I was able to discover about these:

• These are official paper models released by Sega. 
• There is no release or copyright date on the templates. The earliest mention of these models I could find online was in 2006, so the models were created that year or earlier.
• The templates are numbered. The Sonic Template is number 1. The Shadow template is number 5, so there must be at least another 3 characters in the series. Let me know if you know who the other characters are and where I can find them!

The templates for these models are both saved at the Internet Archive and may be downloaded here and here. From comments online, people universally agree the heads of these paper models are complicated and require patience to build. You have been warned! :)

UPDATE 5/4/25: Since posting this, I have discovered more information! The series was released in 2003 and included six characters. See all the characters offered at this archived Sonic Team page.