Trog Wanderers are mysterious, slow-moving enemies in Skylanders: Giants. As you hit a Trog Wanderer, they will shrink. And when it gets half your size, it will run at you to bite. The Trog Wanderer will regenerate its health and regrow if left alone.
Despite the fact that it is introduced in Chapter 15, it first apppears as a ghost near the Water gate in Aerial Attack!.