Can't reverse a digital-animation

Can you tell us more about that clip is?

Any "regular" clip can be reversed in the timeline by selecting and do Modify->Retime->Reverse Clip

If you have something on the timeline, like a sequence of still images or clips, that you want to reverse, you have to make it into a compound clip first. Select all the images, press option-G to make a compound, then apply the above command to reverse the compound.

We're trying to guess your meaning. Is a digital animation a clip whose parameters you've animated with keyframes in FCP that you want to reverse, or is it a clip of an animation, in which for FCP it's just a clip.

What are you doing to reverse it? Are you using the retiming tools? There's a function to reverse clip. Does that not do what you want? What is you're doing? What happens when you do it? And what did you expect to happen?