SCP-513

"You’ve seen it. Now he can hear you. You’ve touched it. Now he can see you. Never ring it. If you hear it, he can touch you."

- Note left with SCP-513 SCP-513 (also known as A Cowbell)is an Euclid-class object in SCP Foundation's containment. SCP-513 is simple, rusty bell. The ringing of SCP-513 causes all who hear it to be stalked by a humanoid abonomation known as SCP-513-1.

Description
Roughly one hour after exposure to SCP-513, victims will begin to catch glimpses of SCP-513-1 when opening doors, walking past mirrors, turning their heads, or performing any other actions that result in a sudden change in visual perception. Upon being sighted, SCP-513-1 reportedly turns away and runs out of view before disappearing without a trace. Questioning of bystanders indicates that SCP-513-1 is invisible to those who have not been exposed to SCP-513.

Sightings of SCP-513-1 reoccur every 14 to 237 minutes. This "stalking" behavior inevitably causes extreme sleep deprivation, as victims are frequently disturbed by SCP-513-1’s presence in their quarters. Victims able to fall asleep before SCP-513-1's appearance report being physically assaulted by it. Upon the victim's awakening, SCP-513-1 flees as usual. This sleep deprivation, along with the mental stress caused by SCP-513-1's behavior, invariably induces paranoia, aggression, hypervigilance, and depression. All test cases but one have ended with the test subject’s suicide.

Descriptions of SCP-513-1's appearance are largely unreliable. Test subjects are unable to provide complete accounts of sightings due to their exhaustion, degraded mental health, and disruptive hypervigilance. However, all interrogations thus far indicate that SCP-513-1 is a tall, emaciated humanoid with abnormally large hands.

In SCP - Containment Breach
SCP-513 & SCP-513-1 both appeared in SCP - Containment Breach. Although ringing the bell will summon SCP-513-1, the player won't be driven to suicide.

After the player rings SCP-513, SCP-513-1 will start stalking the player. The sound of loud breathing can be heard and SCP-513-1 will occasionally be seen in the player's peripheral vision. Attempting to get closer to SCP-513-1 will result in it vanishing. The only way to get rid of SCP-513-1 is to destroy SCP-513 by processing it through SCP-914. Upon destruction, the loud breathing will cease.

Trivia

 * SCP-513-1 and SCP-513 were originally included in the initial release of SCP - Containment Breach, but were removed in v0.2.1.
 * An audio clip of SCP-513 would play randomly over the intercom and the player would occasionally see SCP-513-1 before disappearing shortly after. It was deemed pointless for the player to escape and was thus removed from the game until its recent iteration.
 * SCP-513's in-game ring is more reminiscent to that of an old church bell, rather than a rusty cowbell.
 * SCP-513 placed #10 on Tats TopVideo's Top 22 Scariest SCPs.