Gosh, it sounds like your son is really afraid, and that this fear is more than just a small fear but an actual phobia.  Have you taken him to see a specialist or counselor about this? Perhaps they know of a way to slowly ease his fears. I do know that one thing we can't do with kids like this is to tell them to snap out of it.

I hope it all works out. Let us know what you end up doing, ok?

My son is 12 back when Ivan hit my son started to act strange he would not do his school work lash out in class, run away from class he often ended up in the principals office where once he was in a ball under her desk crying.  He would sleep with a stick.  I asked him what the stick was for he said after he goes to sleep he gets woke up because he hears voices.  

  I got him appointments with his piedatrican and we put our heads together.  Of course everyone else wanted to chalk it up as ADHD and then let it go.  That didn't make sense to me because he didn't show signs before.  So after much debate his doctor and I agreed to treat him for Seperation anxiety and Depression which he showed all but two of the symtoms for.

  Here is one of the websites that helped me out:
http://www.healthyplace.com/site/childhood_psychiatric_disorders.asp#anxiety

  Well his doctor put him on Zoloft .25mg and he was on it for a year then all better he has been off of it for some time now.   I read that if you catch it early enough it could help prevent Adult depression later in thier lives.  

  I wanted to say, if your son is really not afraid of alligators and is just telling you that, there has to be a reason for it.  Children at 6 do not have cognative thought they don't do things to make you miserable or embarrase you they do it  to get their needs met or wants met.  I guess that is your challenge figure out what his need or want is?

  So far seems to be great no more trouble at the principals office back to the quiet happy kid he always was.. Other then a few smart comments but hey he is 12..lol

  Well I am not a doctor but I hope I have helped you with my experience.

Wolfgaze

Hi,
I have a great book recomendation for your son that you can read along.
Snip Snap!: What's That? by Mara Bergman (Author), Nick Maland (Illustrator)

http://www.amazon.com/gp/product/0060777540/104-7842024-4321503?ie=UTF8&tag=babble-20&linkCode=xm2&camp=1789&creativeASIN=0060777540

However I agree with Wolfgaze and you need to get to the bottom of it. consulting with a child development specialist could help.

Zenmeer