For the 25th Anniversary...a solo-Tails pin has been made!
This is a nicely detailed metal and enamel pin. It has just Tails in the winged star ring. He's shown smiling and waving. The ribbon banner at the bottom has "25th Anniversary Tails Miles "Tails" Prower" instead of the usual Sonic logo.
This is a SegaShop item, but it was 'limited edition', so it already sold out before it could appear here on Gear. While it was active, it was 11 dollars for 1 pin. It isn't very large...so it's a little on the pricey side. However, it was meant to be an exclusive/limited thing.