Copycat copies precomps and their nested comps so you can edit a new version without changing the original. It is a free micro tool in Motion Dock.
Select a precomp layer in After Effects, then click Copy. A new layer appears directly above the original, using its own copied comp tree.
The All chip is the default. It includes every nested comp.
Make another version
Duplicating a precomp layer in After Effects keeps both layers pointed at the same source comp. Copycat creates new comp sources and reconnects the copied layers to them.
For example, if Title card contains Text animation, Copy creates Title card copy containing Text animation copy. You can change the text animation in the copied version and keep the original version intact. Make your first copy from an open dock.
Keep shared parts when you need them
Use 1 level to copy only the source comp, or Pick to choose which nested comps become independent. Footage, solids, and other non-comp sources stay shared at every depth.
To make an existing layer independent without adding another layer, Alt-click Copy. You can also copy selected comps directly in the Project panel. The controls reference explains selection priority and what each action changes.