When Lizards Attack

This is not a post I would normally put on my blog, but it was too cool not to share. Louisiana has a lot of fascinating animals, but this is the first time I've seen two lizards that look like this. I noticed them outside my office window and became fascinated with their fighting each other. I took several videos with my Nokia 6882 and although the footage is not really high quality, you can see well enough to enjoy something that is rarely seen. These two guys are huge and their heads are shaped differently than most of the lizards I've seen in the state. Anyone have a clue as to what type of lizards they might be?