An odd, stubby bank. Looks to be made of rubber. The likeness is not all that great, either. These were plentiful on Ebay in the early 2000s. It was not very expensive. Where are all these things coming from? Note that it is not the new-style green-eye Sonic.
This is now suspected to be a BOOTLEG ITEM. It is not confirmed a fake, so it stays...for now. The later banks may have been created from the bank seen below.

These plastic coin banks were available in 1998, and this set was found at a comic shop in the USA. The banks reduce each character down to a super-super-deformed head, arms and feet. There's only a tiny bit of the chest showing, and no legs at all. Retailing at $20.00 each, they were more than what was published on Ebay later on. The Knuckles is a bit better looking than the Sonic because the piece between his eyes is supposed to go all the way down (and Sonic is technically a cyclops, while Knuckles isn't...though here they both aren't)