Wereskags are people turned halfway into Skags by the so-called "cure" for the zombie disease. The cure was based on skag DNA, as they are supposedly immune to the disease. Dr. Ned may have intentionally caused the wereskags because he created the zombie disease in the first place. Anyone attacked by one of these foes also turns into a wereskag.
Wereskags have moderately low health and are limited to melee attacks. Like full skags, they are quite fast and can jump very high. They have the bony head and shoulder armor of a normal skag, but also the vulnerable critical zone inside their mouth. When they are low on health they will glow red, an ability which lets them (very rapidly) regenerate to full health after a period of a few seconds, also causing them to go berserk, dramatically increasing their movement, attack speed, damage, and resistance. Despite all this, however, they are extremely vulnerable to incendiary damage, so liberal application of fire elemental weapons, Action Skills, and grenades is recommended when facing Wereskags. As Wereskags are not considered 'zombies', corrosive weapons are also effective against them.
Unlike Zombies, Wereskags do not resist elemental attacks.
Killing a Wereskag does not increase your Skag killcount.
All Wereskag bosses have the ability to drop artifacts for all player types, depending on level you can skip artifact levels, IE; if you have Roland with Shock on level 3, you can pick up level 6 artifact and pass 4 and 5 levels.
They are an obvious reference to werewolves, following the horror movie theme of the Zombie Island of Dr. Ned, and they even turn into wereskags at the full moon.
They only have two jaws, unlike normal skag, which have three.