I'll admit that I had my doubts, but I'm not quick to scream "hax!" or "shopped", so I was waiting to see. I just got Ifrit's Harpoon today, so it's definitely legit.

Also, what gear do you have your retainers equipped with? Are you doing quick exploration, or the 18 hour one? I got mine during the quick exploration as a BTN that is ilvl3 at level 22 (I've been lazy with gearing because it hasn't really mattered yet, leveling is still pretty quick, and I don't want to make new gear for her every other day). I am assuming that gear doesn't really matter, and it's all RNG, but I'm still curious.