Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Nightmare Fuel: Crysis
The reality of wearing a Nanosuit. While in reality, it seems like a regular powered armor suit, in reality, it's a symbiote-like device that fuses with its user (unless if you wear a protective suit that prevents its fusion like with Prophet), turning the person into a Humanoid Abomination.
The Manhattan Virus: Infectees in their late start getting growths on their lower abdomen and pelvis, and those two die by the disease ''melt''into a reddish-pink goo. Luckily, it is not contagious.
However, It is commented that, given its lack of contagiousness, as well as the relatively short range of the dispersal spears, the virus might be a sort of "beta" version, undergoing a controlled trial-run in New York in preparation for a worldwide dispersion of the perfected, fully contagious product (which could be what the Central Park tower was meant to do).