@AndyD273 For an amorphous creature like that, most if not all of it would be made in the game engine, since you're generating the mesh according to changing control geometry at runtime.
If you wanted something with a more rigid structure like a spider, modelling it/its parts in Blender or other 3DCC tool first would be a good strategy, since they have better tools for sculpting specific shapes.
What engine are you using? And do you want to match the look of that minic creature exactly, or do you have a different visual target in mind?
@DMGregory I'm making it in Godot. I'd like it to be pretty similar to that, but just about any black spider like creature would probably work. As of right now I only really plan to have one type of enemy, but they will get bigger depending on health. The boss will basically be a giant. It might change.
From there, it sounds like you can use the SurfaceTool and MeshData to construct a tube mesh following that curve. We have some Q&A showing how to do something similar in Unity, which shouldn't be too hard to translate.