Recently, while searching for snakes at a river nearby my house, I found a lizard with two tails. This rare animal wasn't born that way. In lizards that shed their tails, like the green anole I found, the animal is born with one tail. When attacked, the lizard drops its first tail and escapes the predator. While it is regrowing, the critter gets attacked
again, this time losing a mere piece of the regenerating tail. While the first tail continues to grow, a second one sprouts from it.
See the one I found in this video
http://www.youtube.com/watch?v=6f5jxczcbP4
Note: The one I found had tails that were vertical to each other, but they can also branch off sideways.