and... how does a frog get a +4 to hide? wouldn't Jump or Swim make more sense?
*edit* never mind, but I still don't see how they would get a +4 to hide. What with their being oddly shaped, brightly colored, and loud.
*rolls a 1 on spot* I see my toe... and it is big!
On the other hand, you could base it off of a 3.5 Halfling, remove most of their bonuses, Convert other ones, such as Hide. Give them the ability to wield weapons as medium size, and go from there. Also, I would like to see the finished product.