Just saw this cool guy at the local fish store in Hallandale, Florida. I have had lesser sirens before, but this guy is huge, and i don't think that he is fully grown yet. Here is my crappy video. Yes, i suck at shooting videos with my phone.
For people who don't know, sirens are fully aquatic neotonous salamanders. They are very eel like in shape. The most interesting features of all sirens complete lack of hind legs. So they really do look like mermaids. The greater siren is classified as Siren lacertina. They are native to United States.
Here are some better pictures from the internet