Like a Shadow Achievement
Stealth Takedown 25 enemies.
Perform stealth takedowns by killing enemies while undetected. Hide in bushes, or against vine or mud covered walls to remain undetected. Kill enemies by clicking [F] when they are near you. You can only stealth kill enemies that are glow yellow when using survival instincts. Trying to stealth kill an enemy that is glowing red will alert the nearby enemies.