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?

  • 1
    $\begingroup$ Ya ha. en.wikipedia.org/wiki/Donohue_syndrome $\endgroup$ – Nahshon paz Feb 4 '16 at 12:49
  • $\begingroup$ @Nahshonpaz wow...you learn something new every day! $\endgroup$ – Philip Rowlands Feb 4 '16 at 13:02
  • $\begingroup$ Please be advised that the word 'leprechaun' is considered pejorative and not supernaturally correct. "Wee Folk" and "Little People" are both considered acceptable forms. $\endgroup$ – Howard Miller Feb 4 '16 at 15:27
  • $\begingroup$ You could invent an entire ecosystem for the fur/algae like sloths have $\endgroup$ – Jan Doggen Feb 22 '16 at 14:38

As has been suggested, make a green kind of fungus grow on their backs. While I don't think having clover leaves is realistic, this can be a parasitic bacteria, which causes sores on the rat's back. It then infects them, and does all kinds of damage to the rat. So you essentially have rotting, living rats. It's like leprousy, but with fungus.

  • $\begingroup$ "Rotting, living rats". Perfect. *Insert maniacal laughter here* $\endgroup$ – Philip Rowlands Feb 6 '16 at 12:43

What about instead of an infection, a symbiotic algae like life form or milli/micro/nano-scopic colonies which feast on the bacteria on the rat and grants its host athletic/magical/etc traits?

Heck, you could even make it a (4 leaf)clover-like plant/fungus/algae to add to the old Irish vibe.

  • $\begingroup$ That would work quite well for the fur colour. However, I do want them to be covered in sores. $\endgroup$ – Philip Rowlands Feb 4 '16 at 12:29
  • $\begingroup$ @PhilipRowlands Well, it could be a parasitic algae instead, actually feeding off of the host, but not killing it fast. Leaching off nutrients, but giving back other chemical or biological agents as part of it's growth cycle. $\endgroup$ – AndyD273 Feb 4 '16 at 14:30
  • $\begingroup$ @PhilipRowlands Yeah, like in my answer. $\endgroup$ – Xandar The Zenon Feb 4 '16 at 15:02

FYI: Nine-banded armadillos, like humans, are susceptible to leprosy. They've also been able to grow it in mouse foot pads since it won't culture in any normal medium.

The bacteria, Mycobacterium leprae, is related to the one that causes tuberculosis.

So you could give the rats leprosy by saying it's a mutation that has jumped species after an infected mouse escaped.


Another possibility would be an animal attack. For example a wasp that injects eggs into the skin. The eggs hatch into maggots that devour the rats from the inside out. The maggots also secrete a green ooze that seeps into the skin of the rat and dyes the fur and skin green.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.