Change Player Controled Model (Shapeshifting)

So, I’m experimenting with a game design where my main character has the ability to shapeshift if certain requirements are met. I know how to add objects and end them, But was wondering how to execute the loadout information for the characters seeing as the Add Object Brick only contains meshes stored in the same file.

Logically I will require some Python to pull an object from another file, but am a noob with python so have no Idea where to start.

Why do the meshes need to be in a different file?

I’m a noob when it comes to Game Design, so I’m not sure exactly how these things work. For the 3 years I’ve been playing around with blender, on and off, I’ve heard that your supposed to put everything in seperate files, and the opposite. So I’m not sure how it’s supposed to work.

I did find a few videos on the subject, still trying to get the thing to work properly though.