These rare horrors aren’t often encountered but when they are, they are often accompanied by some sort of military unit. It may be that these creatures have been engineered or created to work as bio-weapons by the military. In this case the zombie is shown in an exo-suit similar to that hooked up to Riverman in Return of the Living Dead 3.
An important thing about these things is that although they are modified in some sense, and possibly armored, destroying the brain should still work on them. It’s also worth noting that these guys are going to kill everyone in the room. If you encounter a mad scientist who is absolutely sure and confident that he has the thing under control, get out of there FAST! There is about a hundred percent chance that these things are going to get out, the controls will break or snap or the seemingly sedate creature will bite you as soon as his controls have been loosened. Remember, the government wants to use them as weapons for a REASON!