GameObject shapeshift script?

Hey, guys. I'm trying to make a unique jumpscare in the horror game that I'm making where you find a little girl crying in a corner. I'm trying to add a feature where, if you get too close to her, she can shape shift into the enemy and attack you. I want it to work like how the ending of Slender: The Arrival (shown below) did. Can anyone who is good with scripting show me how I can do this? If so, it would be much obliged. Please and thank you!

Thanks in advance,
DarkwoodProductions

P.S.
Here's a video of the ending to Slender: The Arrival (which is #madewithunity btw) to give you a better idea of what I'm talking about...

 

This would best be done not with scripting, but as an animation, in your 3D modeling tool. Any good 3D artist ought to be able to whip up such a transformation for you.

(But note, it pretty much has to be planned for from the beginning, because the two meshes need to have the same structure. If you're starting with two models that were built completely independently, it's going to be really hard... probably your artist will simply rebuild one or both of them.)