This is an Ameiva, also commonly know as a whiptail. These guys are so awesome. You will find some that have a bright blue tail on them. As my old biology teacher said, “They are speedy little bug eaters.” It is funny to try to watch them run on tile, they tend to slide. But put them in the grass and they are gone in no time. I have had to rescue a few from my cats before. They can lose their tail and most of it does grow back. I remember seeing a few at the last house I lived in where their tail was growing back. I always looked at them and ask if they were going to try to come back in the house. These guys are perfectly harmless also.