Item #: SCP-252
Object Class: Safe
Laconic Containment Procedures: A breeding pair of SCP-252 is kept in Foundation custody. There are speciments in the wild, containment is not required, but civilian encounters must be covered and, if needed, amnestics administered.
Laconic Description: SCP-252 is a sub-species of the Humboldt Squid that creates illusions, causing people to believe that is a giant sea monster.
People that fall victim to its hallucinations will believe they're real and will try to rationalize its existence, no matter how crazy they may seem. When seen through video, the hallucinations by SCP-259 are always reported as fake looking, but still quite frightening.
Additional Context: The Foundation thought the hallucinations by SCP-259 were real, because of that the article has a crossed out description and containment procedures that treat the SCP as a big, mean sea creature.