The Scab Mauler is an Enemy in Warhammer 40,000: Darktide. They are heavily armored and wield a large chain axe. Their attacks are quite slow so you can avoid them by dodging. It's especially important to avoid their overhead strike - this is very slow but if it hits you it does huge damage.
The Mauler's helmet is made from strong Carapace Armour, so you are actually better off using body shots rather than headshots to take them down.
Scab mauler Chainaxe in Darktide
Scab Mauler from the back
Scab Mauler Carapace Armour Helmet in Darktide