Mimic Chests. You'll eventually encounter some chests that are monsters and they drop cursed items when defeated.
yeah, im not sure what triggers the appearance of mimic chests. Not sure if they only start appearing at certain levels (desert and beyond) or if its based on Celica's level. Right now, my Celica is level 80, but when those mimics first started appearing, i got a game over because they were slightly stronger then the desert level. I didnt have any health potions at the time, so i lost. 2nd battle on, i made sure to have 2 health potions on hand at all time, because Mimics hit hard. But i've been winning all my battles with them since then. So now i have multiple lust fruits.