You can retarget the animation of a characterized character to another one in the same scene. You can also save takes of animation to be retargeted onto any character.
Using generic biped or quadruped skeletons lets you reuse animation on different characters.
The options that let you quickly retarget animation between characters are found in the Character Controls.
Motion Reduction controls to adjust the amount of motion transferred between the chest, neck, head, and shoulder body parts of your source to the corresponding object of your target character. See Motion Reduction properties.
When you retarget keyframe animation, the Reach properties are also retargeted to the target character. This means you can take the precise keyframe animation you have developed for one character and reuse it on another character.
When you select the > Edit > Controls > Retarget Rig, keyframes are copied directly from one Control rig to the other, without plotting. The Character dialog box that appears lets you select how you want the retargeting to be done.
The quality of your animation is preserved and adjustments for any difference in size between the characters are made automatically.
In order to retarget keyframe animation properly, you must have an equivalent setup on both characters. The best way to achieve this is to create identical Control rigs for both the source character (the character you want to retarget from) and the target character (the character you want to retarget to).