Fred (and Persephone by association), thrives in a filthy environment, which is no problem with Fooker, but Nick and Sharon, who have allergies, require clean environments, leading to conflict with the molds. Both molds also gain nutrients from eating decomposing food, can be destroyed by cleaning products such as bleach, and, like humans, require sleep. Fred has learned that he has the ability to control people's bodies by planting pseudopods on them, and used this ability to force Trent to perform various embarrassing and illegal acts (culminating with running round the GPF offices clad only in a cape and screaming that he was 'Willy Wombat, walloper of the wicked and warden of the weak'. It is implied that Persephone can also do this, although she has never done so (Fred wanted her to help him possess Sharon and Fooker so that they could have sex, but Sharon disapproved).