Roguebook

As you uncover more of the map throughout each playthrough, you have a chance to uncover a clone of Fugoro. When you find him, he will steal one of your treasures and then hide in a different, covered part of the map. It's usually not that deep, so you won't have to burn off that much ink to find him again (the hex he's inhabiting is also visible to you). It's worth it to track him down each time, both to get your treasure back but also to get a second, random treasure when you uncover him the second time. Do this on 10 runs to unlock the cheevo. Note: clone Fugoro is not uncommon, so you will probably get this through normal play as long as you prioritize finding him when he hides each time.