He is a Keter-Class entity but he isn't an SCP. he is lethal, has no bones, no weakness. Instead. he is a Screamer where he Screams at 150 Decibels. And... YOU CAN'T OUTRUN HIM. HE CHOOSES HIS TARGET AND FINALLY. ATTACKS BECAUSE HE FOUND YOU

He has Mental Disorders, and Mental Illnesses And he hates needles.

Look behind you