Doctor: Mitra, with the special devil fruit "Mulch mulch fruit"
It has elements from all three types of devil fruit: It transforms the users body into mulch, having maggots crawling (that's the zoan part) and fungi growing around the body. The fruit can generate absolutely huge maggots and the fungus can grab into almost anything, which can be quite dangerous, as its spores can make shrooms grow inside targets and the mycelium can drain their blood. Also, the mushrooms can patch people up, creating shroom organs to substitute their damaged organs.
Even though this fruit is very powerful it has the drawback that the user can't generate any new mulch, but must feed on organic material.
Unless their body is needed (for example, to use a sword, she's pretty good with two handed swords and sabers), Mitra will spend most of her time moving through the ship as a fly, a termite or a lil grub.
