Beware the Habu Snake
Habu ( Trimeresurus flavoviridis ) are poisonous pit vipers found on Okinawa. As with most snakes they keep to themselves so you’re very unlikely to see a habu in the wild while on Okinawa. Unfortunately you are likely to see one sitting at the bottom of a bottle of Awamori (Okinawan Sake). Similar to the worm in a bottle of tequila the snake is thought to give the alcohol an extra kick.
Another interesting fact about the habu is that in 1910 someone made the decision to import Indian Mongooses into Okianawa to control the habu population. The mongoose has now become a serious pest on Okinawa, killing and eating virtually every native creature on Okinawa, except for… the habu.
TRAVEL 67 : Chris Willson Photography 
Habu is the main reason I’ve been reluctant to visit Okinawa. My rational mind knows I’m in no danger, but my phobic instincts just don’t care.
I remember, as a child, going on school field trips to a snake farm and watching a habu and mongoose fight! What recreation for a kid. NOT! That’s so sick! As an adult, I would not allow my child to watch something like that. What were the adults thinking anyway? It was an experience I never forgot, that’s for sure. While living there, it wasn’t so much the habu I feared as the Portugese man-o-war I got into. THAT was an experience.
Same thing happened in many places where one pest was supposed to kill another – in Australia the millions of rabbits, that Europeans brought there were supposed to be be killed by mongoose (one mongoose, many mongeese?), who found various small marsupials, like wallabies, much easier to kill!