Hive Mothers are slightly smaller than Rat Kings, and visually, have large horns and sickly green color of their perforated hides.
They do not spawn any Plagued Vermin, but instead can launch a barrage (bypasses most obstacles and does not count as missiles) of 1-4 Sand Wasp-like insects. Each of those explodes in a very small radius for average Poison damage. This attack has a minimum range.
In melee, Hive Mothers can attack with their claws, delivering slow swipes for average Physical damage.