This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Predators
When Cuchillo goes missing, they find him down on his knees, his back to the group, in a clearing. Royce quickly deduces and proves that Cuchillo is surrounded by traps, and he's presumably wounded, as they can hear him saying "Help me." After a quick debate, Isabelle shoots Cuchillo to put him out of his misery... And seconds later, the corpse say "Help me." Then the camera switches angles, and you see that Cuchillo was dead for the entire scene.
The Berserker Predator's face when it unmasks itself during its fight with the Classic Predator.