The only one I can recall seeing, outside of the Original Series, comes from this mission - where I believe it was eventually rescued and brought back to HQ, although I have no idea what happened to it after that.

I don't think your questions have ever been addressed in any missions so far, so this is all guesswork, but I imagine that they'd be generally similar to minis (seeing as they are also created by spelling mistakes). So they might be partial to eating bacon, raw eggs and fangirls, and can probably be trained by anyone with sufficient patience to do so. As for whether or not they can breed, I'd be tempted to say no, that they can only come from the appropriate spelling mistake, but I don't see any reason why they couldn't if you thought it was funnier that way.