Venetica

Gripper Queen Slayer: The Judge in the courtroom in the Outer City will give you this quest. To make certain you get credit for the quest, don't kill the queen until you get the quest in your log.

In the catacombs, go to the SW corner of the catacombs (accessed from a southbound tunnel from the central chamber, and the quest will give you a green dot locator on the map) to the Gripper Queen's chamber. You will fight a number of smaller grippers on the way. Stay behind them and hit them (hammers work well for this) from behind while avoiding their claws. Use the same strategy for the queen. The slow time ability in the second twilight circle can help with this and give you time for more hits. Your best bet is to lure the little grippers away from the queen one at a time so you don't have to fight on multiple fronts. Once the queen is dead, the achievement will pop. Take her beacon and head back to the judge for reputation and reward.