Trivia: Crocodiles and Alligators have some of the strongest and most efficient immune systems in the world. They're not the strongest but in addition to being able to fight of the kinds of infections that you'd expect an animal that spends most of its life living in filthy swamp water and regularly acquiring open wounds to get, at least one study has shown that crocodile immune cells are able to destroy immune deficiency viruses and things like herpes which normally stay in an infected organism's system forever.

This has been a bit of random biology trivia.