Why is this issue occurring with my models?

I’m building a game using Unity, and have modeled the zombies for my game in Unity as well (collection of cubes and cylinders) (not the most practical method)

95583-title.png

When the zombies are moving in-game, the model overlaps itself and looks terrible.

95584-capture.png

Is there any reason to why this is happening? What can I do about it?

Most likely this has to do with the scaling of each child game object. When you want to make custom assets in Unity I recommend using ProBuilder
It’s an excellent tool that should be built in.