That could be it. It looks like it is upside down because the spikes/whiskers seem to come from the wrong place.
The place that I get my fish from is a very small shop, in a small rural town, and I don't recall seeing them sell this particular breed at all. So I'm wondering if he has stowed away...
You might be right.
He still looks a bit strange compared to the ones on Google images, but close enough I guess.
I'm thinking he must have ended up in my tank when he was a baby. Maybe hidden in some plants or something, because I've never actually bought a Corydoras until about 2 weeks ago...
I'm not sure how long I have had this mystery fish as he only comes out of hiding on very rare occasions, but the first time I saw him was a few months ago. When I saw him, I was like "What the heck is that?"
To me he kind of looks like what you might get if you bred a yoyo loach with a...