I'm going to guess that it's not brooklynella or ich, based upon the fact that I've had this guy for a year and a half and he's never shown signs of brook before. Plus he's been through hypo when I first got him, which probably would've taken care of that along with the ich he had when I first got him. And while it's not impossible, I have to think that it's not either. I know it's not ich. And it doesn't really look like brook, either, as it's a cottony puff on his side.
My guess is that it's probably a fungal infection of some sort. I suppose I should probably pull him out and give him some dips with an antifungal med. Oh the fun...