Florida is home to three Plestiodon species, which all look very similar as juveniles. The southeastern five-lined skink and the common five-lined skink both look a lot like the image above as youngsters. You can tell the five-lined skinks apart if you can turn them over: the common five-lined skink has a line of broad scales down the ventral centerline of its tail, and the southeastern has lots of little, same-size scales. The broad-headed skink is differentiated from the other two by its five, rather than four, labial scales.
(With apologies to the Virginia Herpetological Society, who made these excellent images, I’m just going to mirror them here, because they are so very useful):
To add to the confusion, despite having blue tails as youngsters, none of these lizards are the “blue-tailed skink“, Cryptoblepharus egeriae, which lives on Australia’s Christmas Island and nowhere else. Plestiodon fasciatus, of course, does have that common name sometimes in North America, even though as adults they lose the blue tails.
As adults, broad-headed skinks turn mostly brown or olive brown, with the males getting the big, angular heads the species is named for, in a bright red color. Broad-headed skinks live all over the southeastern United States, eating a wide variety of insects, spiders and invertebrates. (The one in the photos above and below is eating some baby Eastern Lubber grasshoppers.)
Plestiodon species skinks are often thought to be venomous; they are not, and are generally harmless to humans.