Tiamat

A classification for SCPs that pose an immediate and irrevocable threat to humanity, and which need to be dealt with swiftly to protect humanity. The class is essentially on the brink of becoming an Apollyon: the Foundation has a small number of last-ditch options to stop the SCP (such as conventional bombardments or prototype weapons), but if these options fail fail then humanity is doomed. The class was first used in SCP-3895. It was later used in SCP-4931 (an SCP-4000 contest entry), SCP-3396 (replacing the SCP's former keter class), SCP-5034, and SCP-5866.