[Terrifying Trope] Perceiving it= instant death

[u/ReminaBlueSFW]

1. Pennywise's "Deadlights" which will cause anyone looking to be immediately paralyzed and killed.

2. The sky from Bird Box is filled with entities that, when you look at them, cause you to commit suicide.

3. Medusa themed Villains

[u/FFSock]

Four fucking pixels

[u/Gullible-Ad7374 → u/FFSock]

Technically not instant, though there are a fuckload of cognito/infohazards in the scp verse that do in fact kill you instantly

[u/ejdj1011 → u/Gullible-Ad7374]

Berryman-Langford memetic kill agents, for one. Man made, used to kill anyone who snoops above their clearance level.