How to create GameObject without adding it to scene?

Hey. I have a prefab with Monster class and a list of monsters. I want to fill this list with instances of this prefab. How do I do that? Monster.Instantiate will create instances of monsters in the scene, I just want to have this list to access at a later time. I’ve read I shouldn’t create MonoBehaviour instances of class via new Class() constructor. I could just set location of these prefabs to place them somewhere far away from game scene, but it doesn’t seem to be good solution.

make prefabs out of other monsters too and add them to your list via inspector , click at the monster class prefab and a list will be in the inspector drag and drop other prefabs in it or use gameObject.SetActive(false);