SCP-173

" SCP–173 has one very key weakness: it is frozen in place as long as someone is looking at it through eye contact. Thus, a victim has a chance of escaping from this abomination by keeping their eyes focused on it; however people need to blink frequently and often do so subconsciously, and with each blink SCP–173 makes a large stride toward a person, and can move across the length of a large room in just a few blinks. Thus, one’s best bet when trying to escape from 173 is to walk backwards away from it while keeping your eyes steady. Also, blinking one eye at a time, while seeming like a good idea in theory, actually does not work at all. Doing so only results in SCP-173 becoming angered and begin shaking (possibly with rage) and kills its target anyway, regardless of being in someone's line of sight."

source: villains.wikia.com/wiki/SCP%E2%80%93173