The leprechaun. A little ginger humanoid dressed in green, with buckled shoes and a matching hat, and a massive pot of (tax-free) gold. We all know them.
Or not. For the world I'm building, I've decided to go down a different path. Instead, somebody who doesn't speak Irish thinks it's short for "leprosy-afflicted corn rats" after seeing some rats with something like leprosy and some green fur, and the name sticks so well that their scientific name becomes Rattus leprechaunae. There's just one problem: as far as I know, leprosy doesn't affect rats.
So, what kind of disease could I give them instead? And would it be possible for this to be the result of their green clothes a green algae infecting their fur?