Stick Around Achievement
Single Player: Using the Predator Bow, pin 10 enemies to walls with arrows
Using the predator bow, make sure to select Heavy Draw and the Carbon Impact tip. Find an enemy next to any surface, and shoot a full drawn bow into their chest, hopefully pinning them to the surface. An easy place to get this achievement is at the beginning of Mission 4, as well as the later areas of Mission 1.
After that, don't forget to retrieve you bow for a credit to the Hunter-Gatherer achievement.