Character: scp-001 (the gate guardian)
SCP-001-CLEF, aka, The Gate Guardian is one of the many proposals for SCP-001 in the SCP Foundation Mythos.
SCP-001 is a colossal angelic being with a flaming sword hotter than the sun guarding the gate of the what is allegedly the Garden of Eden from the biblical Old Testament, located where the Tigris and Euphrates Rivers meet. This would mean that SCP-001 is also the Archangel Uriel. If you approach it and refuse its orders to turn around, it instantly slashes and vaporizes you. At one point, SCP-001 told a man to "prepare" without context, eventually leading him to found the SCP Foundation.
It is classified as both Euclid and Keter.
SCP-001 also appears in SCP-1730: What Happened to Site-13?
This tag implicates scp-001 (learn more).