Here's a Sonic X keychain, released in 2007 by an unknown company, but currently being sold by ToyCup.
Currently, it is avialable on the ToyCup website. www.ToyCup.com and also in the SonicGear Sonic Store. The figures appear to be metal with enamel on slides. Sonic is in a pose from many of the current shirts, Rouge is standing around, and Shadow is in action. You also get the "Sonic X" TV show logo. This doesn't look very large...but there is no real scale to the photo.