That gives a whole new spin to stories about witches if you imagine the antagonist (or protagonist, of course) as a fish. Fish need to live in water, so presumably it takes a bubble of water with it wherever it goes. Or it lives in a water-heavy cloud, so it rains heavily wherever it flies to.
The witch is also known as a lefteye flounder; perhaps suffering from entrenched prejudice against lefties?
The Arnoglossus scapha (or lamb-tongue) is native to China and New Zealand (and presumably lots of smaller countries in between...). No wonder witch-hunts didn't take off in Europe until contact with the far east was starting to be slightly better established. Long-distance sailing would have exacerbated the problem more than overland routes, I presume.
I had initially assumed it might be partial to exotic lettuce in the neighbor's garden, but given the righteye flounder eats worms and crustaceans, perhaps not. Although side salads are often a nice accompaniment to a heartier main.