One thing I noticed in the Secret Rings game is that in the JP ver., Erazor would often mispronounced "Harinezumi" (Hedgehog) for "Nezumi" (Mouse/Rat) but in the US ver., it was changed to make him mistaken Sonic as a rat. Is this a case of translation issue?
When Erazor first encounters Sonic, he refers to him as a “Blue Rat” (”Aoi Nezumi”) and laughs when Sonic sets it straight that he’s a Hedgehog (”Harinezumi”)
Afterwards, he frequently refers to Sonic as “Dobu Nezumi” or “Aoi Dobu Nezumi” which basically translates to “Gutter Rat”/”Blue Gutter Rat” respectively. Which more strongly suggests a malicious insult AND purposeful species mislabeling rather than ignorance as to Sonic’s species considering that Sonic originally and continually asserted that he was a Hedgehog. In the cutscene in which he summons the Ifrit, he states in response to Sonic ONCE AGAIN asserting that he’s a Hedgehog that this assertion doesn’t change his belief that he is “worthless vermin”, hence the continual “Rat”/”Gutter Rat” insults.
So basically, Erazor was just saying it to get under Sonic’s skin.