One of these Instantiates change name and/or tag on prefab, dunno understand why

I use these instantiates:

// The following lines of code is not executes after each other as seen here.
bigDummyGO = Instantiate(dummyGO) as GameObject;
flipCard_GO = Instantiate (Resources.Load (endCardName)) as GameObject;
flipCard_GO = Instantiate (Resources.Load (endTag)) as GameObject;

After these i change name and tag on the GameObject (like: flipCard_GO.tag = “test”) that receives the Instantiates but still the name / tag is changing on the actual prefab and not just the GameObject (bigDummyGO, flipCard_GO). Why is the prefab changing and what do i do wrong?

None of those should change the prefab’s name.

If you were looking for code that DID change the prefab, it will be code that does not instantiate, such as this:

prefab = Resources.Load<GameObject>( "prefabpath");
prefab.name = "My new prefab name"; // changes the asset name on disk.