I saw it less of a case of they were actual jokers, more along the lines of they have a very rodent-like appearance because of their front teeth, so they use illusions to conceal it.
Canines was easy as it fits into established vampire lore and gives a traditional feeling house.
Pre-molars was harder but i just imagines a very animalistic appearance.
Molars was somewhat easy as they would be very inefficient and I can envision them being akin to savages and possibly even engaging in self mutilation in order to allow them to use their rear teeth and being keen torturers. Murderers on the battlefield, Enemies who die there are the lucky ones…