Hi.
I am not very experienced with shading objects, but I think to make them "wet" you could put a reflective shader between the surface shaders of the objects and the objects input. Maybe you can then restrict this shader by hight, I don´t know that. But as your crocs look quite active, I think they could be wet all over.
About waves etc around them, the best way I can think of ist to use the painted shader. Build a surface layer with the displacement and color that you want for your foam, put it on top of yourwater shader and restrict it with a painted shader. Then paint in, where you want to have foam. Image maps could work too.
Great Crocs and nice start on the terrain, needs some color variation in my opinion.
Best Regards,
J
I did a little test, although I don´t know if my method will work with your crocs.