Nerodia fasciata pictiventris, the Florida banded watersnake;
Alachua county, Florida (09 September 2006).
This is a caramello (as I call it) variant of the non-venomous and entirely unaggressive Florida banded watersnake, a highly variable subspecies of the Banded watersnake. I tend to mostly see caramellos in Lake and Alachua counties, though they do occasionally pop up elsewhere as well. Usually, this species is much, much darker in adult form.