Here are 2 plushes from th e"Sonic Project" line.
This line was created by none other than "Toy Network", makers of some of the notoriously bad mutant gear plushes. They began operating under Sonic Project around later than the time of Sonic X, but still used the X art for their tags. These 'project' dolls were supposed to be better quality than before but...because it's them...kind of not.
The Sonic has mini/wrong ears & suffers from a bit of 'big body'. However, the hands & feet are nice & large & the head is just fair. The Knuckles has tiny feet but good big / well-formed fists. But then...look at his embroidered eyes...they're not sewn on evenly & he looks strange.

Each one has good and bad points, but they average out to just fair/poor as official plushes go. Probably not all Knuckles have mis-sewn eyes, but getting one like this would be a dissapointment for sure. Fortunately, these older dolls don't show up much any more.