The character rig was designed with the purpose to simulate how a bunch of rats in a trench coat would behave.

This character can also jump, grab objects, and dance while maintaining its wobbliness.

The bones below the waist act like a regular character rig would, but all of the bones above are driven by physics.

Every bone above the waist is driven by a hinge joint. The settings were tweaked just right to make it wobbly, but still upright when standing still.