Secure, Contain, Protect. That is the mission of The SCP Foundation.

SCP-096 is a humanoid creature, standing approximately 7.8 feet (2.38 meters) tall. Its body appears emaciated, very little muscle mass and clearly malnutritioned. Its skin and eyes lack pigmentation, and the subject appears void of body hair. Its arms reach out approximately 5 feet (1.4 meters) in length, highly disproportionate to the rest of the body. Its jaw can open four times more than that of the average human. Other than these few characteristics, SCP-096 appears human.

In 1986 there was a surge in the number of people entering the Himalayan mountains, and never leaving. Those who did escape reported hearing a loud ringing alarm, so loud they had to cover their ears and run, and even then suffered severe or complete hearing loss. They may not have known it at the time, but they had just come into contact with Siren Head.