Baby Copperheads look exactly like adult Copperheads, only smaller, and they have a bright yellow or yellow-greenish tail, which they wiggle to attract small lizards and frogs which think that the tail is a worm. Here is a good photo of a baby Copperhead, in which you can see that yellow tail: redtailboa.net . Many harmless snakes are often killed by ignorant people who think that they are "Copperheads".
