Cathy is Jonas Under's worker fairy. She accompanies him when he sets off to follow of Ann on the bloody road.
She seems very attached to Jonas but treats Ann with less respect, which sometimes earns her to be snubbed by her master. When some of Ann's silver sugar is stolen, she blames Mythrill Rid Pod, claiming to have seen him do it. However, it is revealed soon after that she is the thief. She acted on orders from Jonas, so that he could steal Ann's creation and present it as his own in Lewiston.
