Uprising - Cowardly Grunt Egg: For this Easter Egg, you’ll want to head into the first building at the start of the level. Inside this building, just below the ledge in front of you is the cowardly Grunt. Make sure to avoid any huge explosions nearby (Scarab skull isn't recommended) and kill everything but this grunt. After killing all the brutes nearby, the lone surviving grunt will begin cowering and begging for mercy. Head over there and listen to his woeful tale for the achievement. Video below shows it in action.