This video goes over Proportional Modifier Setup which can be applied on-to existing character rig to create multiple character variation from the same base rig. This approach can also be used in fixing, fine-tuning or polishing the look, appearance and silhouette of a character during animation.
Watch here: https://vimeo.com/182679471
You can watch Morphing Character Setup Demo here: https://vimeo.com/180397712