A D'ni who somehow bought the Age of Teledahn cheap. When he took it, the Age's ecosystem had corrected itself after Ventus's modifications. Manesmo started the harvesting of spores again, perhaps for makeing bread, and thus he made a decent amount of money. Mensmo also saw Shroomie frequently and even found her nest.
However, he was doing lots of stuff in the dark, like trading slaves to Rebek. For this purpose he kept cages and a secret backside, obviously hidden from the Guild of Maintainers. It seems he was suspected and a major inspection was going into his illegal activities but nothing was found. This occurred shortly before the Fall of D'ni.