I've just started what I hope to be a progression of tests using this wolf rig. I really enjoy the design of it and the rig is pretty good, especially compared to most quadruped rigs. I had to do a bit of re-rigging so that I could control it in the ways I wanted. After looking at some reference I found at this amazing site: http://usa1.framepool.com/en/creative/animals/, I noted some things. Primarily the up and down motion of the hips, chest, and head areas. Wolfs seem to have a pretty solid chest area, and the head is almost detached from the movement of the body and moves around smoothly checking things out as they go along. Like most quadruped rigs, the hips controlled the chest and head portions of the body. In order to get that offset bouncing motion, you have to counter animate the translation up and down and the rotation forward backward, but that would cause a lot more movement to go into the head and I'd be spending a lot of time counter-animating the head to stay nice and smooth. If I wanted to dig into the rigging more I would consider re-rigging the neck area so it is very free from the movement of the body, but...that's a lot of work and real wolves heads aren't actually detached from their bodies. Instead I added a controller to the mid-back that could move both the hips and chest, like most COG nodes, but I still have the flexibility to translate and rotate the hips and chest separately. I also had to add to this rig specifically a controller to be able to pose the ankle better because that shape change is important for getting a sense of weight and a nice springiness to the overall movement.
My plan is to do some cycles of walks, runs, etc, and build to a more full-on test, but in this way I'll have been figuring out the mechanics of what make the motion wolf-like, become comfortable with the rig, and start to understand the personality of my wolf.
I just did a pretty generic trot cycle with this guy. Nothing too crazy yet, but working on finding a balance between squooshy cartoony movement and realistic motion. Also, because I hate the robotic-ness you get from doing just one cycle, I actually animated this as two cycles (of foot steps) so that I could vary them a touch to give it a bit more of an organic feel to the motion. You can see in the front view how the feet come down at slightly different places each time. And that blink I put in there.
This is just first pass stuff, so if you have any critique or comments feel free to send them my way.