I designed these 2D characters in Procreate and rigged them in Unity. They each use the same skeleton, and have both FK and IK setup. I made good use of the Photoshop Plugin inside of Unity in order to auto generate my sprites for each part of the body. I then gave each body part a category in order to swap them around and create custom characters. I wrote up documentation on this process because I failed to find any for the newest version of Unity at the time. You can find that documentation on my blog! : )
FK skeleton demo
IK limbs demo