As part of the Alive! animation course (purchased and accessed on the P2Design Academy website) I've been studying, I've animated a run cycle for a squirrel model. The model and rig was provided by the animation course and the animation was done in Blender.
The process of animating this squirrel started with 'blocking' out the keyframes to build the animation upon. Then the animation would be supported by additional frames next to the first and final keyframes. After this, it was a gradual process of making many adjustments to the animation curves in the graph editor, as well as make additions and tweaks to the animation frames, improving the animation of each bone one at a time.
As the course specified, I put emphasis on arcs, follow-through/overlapping animation, and squash and stretch. Emphasis was also put on watching footage of the movements of squirrels to develop the habit of referencing real footage for accurate animation. This has taught me a lot about animating 3D characters, but there's still plenty for me to learn from this course.
Squirrel Run Cycle Render
Squirrel Run Cycle Side View Render
Squirrel Run Cycle Front View Render