SCP stands for either Special Containment Procedures or Secure, Contain, Protect, which is the SCP Foundations Motto. The SCP Foundation is a large organization specializing in containment of anomalous creatures or objects to protect mankind and to study them to create scientific breakthroughs.
( This is the third book to Sans' House Guests, you should go read that and Shadows of Remorse before you read this because you will be confused on what the heck is happening! This is an original crossover story between Undertale and CreepyPasta where Sans is the main character and makes some CreepyPasta friends! I ow...