They are actually enemies for the Towers to defend against. These are characters on our upcoming Tower Defense assets pack that will be found on MobileGameGraphics.com mobilegamegraphics.com/
We create assets that we use on mobile games. Right now I created 23 characters with walking animation for the towers to murder and mutilate. Each one took about three days at about 8 hours each, painstakingly painting each and every parts and readying them for Animation using Spine. I love that program. It allows me to manipulate meshes that could only be done previously on 3D animation.
The Trees, Bushes, Items, Tiles were created by my Coworker Andrei as part of this project.