I found this guy in my driveway this morning. I live in Northern Florida, near Jacksonville.
I initially thought that it was a baby snake (note the black on brown lengthwise stripes), but it moves very slowly and methodically, like a slug, perhaps. Never saw a slug so long and skinny. He's about 3.5 inches (90mm) long, and can hold his head up high to look around, raising up almost a third of his total body length.
Maybe some kind of worm?
The "hammerhead" style head is what is making me scratch mine.