Per 
Item #: SCP-4397
Object Class: Euclid
Special Containment Procedures: SCP-4397's chamber is to be constructed in similar fashion to a low-rent apartment, equipped with a bedroom, a living room, and a bathroom. SCP-4397 is to be fed 3 times a day like would any other human. Once a day, at least 3 D-Class personnel accompanied by at least 1 security guard are to enter SCP-4397's chamber to perform regular maintenance procedures, along with bathing SCP-4397.
Should SCP-4397 desire to converse with someone, he may request for 1 scientist to voluntarily enter and converse with SCP-4397 for no more than 60 minutes, with the entirety of the engagement being recorded and monitored via both video and audio. No scientist is to be forced to speak with SCP-4397 if they do not wish, and in the event no scientist is either available or willing to speak with SCP-4397, he is to be told so.
SCP-4397 is to be kept in his constraints at all times. Failure to do so will result in SCP-4397 transforming into SCP-4397-1, and the death of whoever freed SCP-4397, along with 3 of the victim's closest family members. Mobile Task Forces are not advised to directly engage SCP-4397-1, unless a high-ranking member of the Foundation is at risk. Mobile Task Forces should attempt to contain SCP-4397-1 through peaceful means as best as possible until SCP-4397-1 reverts back to SCP-4397, if it ever does. If recontainment is not possible, SCP-4397-1 will transform back into SCP-4397 and be ready for recontainment after all 4 of its targets have been killed.
Anyone who witnesses SCP-4397-1 must be subjected to several psychological evaluations and therapy for any possible psychological and/or emotional trauma.
Description: SCP-4397 is a 1.93m tall Caucasian male in his early 30s. SCP-4397 displays all physical and psychological characteristics of a human being. SCP-4397 is at all times constrained by a concrete slab with 2 holes, one for each arm, measuring at 30cm long and 12cm wide.
SCP-4397 is docile and cooperative with Foundation staff, willing to perform whatever instructions he is given. However, when freed from his constraints, SCP-4397 immediately undergoes a transformation. Several tentacle-like appendages will begin to grow from SCP-4397's back, with SCP-4397 immediately beginning to lose all human features. Its skin and clothing will begin transforming into a black, gelatinous, flowing substance, while it simultaneously loses all capability of speech and presumably, higher reasoning.
After the transformation is complete, this "new" entity, which from here on out will be designated as SCP-4397-1 to differentiate from the human SCP-4397, will proceed to relentlessly hunt down the individual who freed SCP-4397 from his constraints. When SCP-4397-1 eventually does kill its target, it will move on to kill 3 other individuals, who on all prior incidents have been identified as close family members of the original target.
SCP-4397-1 seems to be impervious to firearms damage, as all attempts at subduing SCP-4397-1 have been met with the entity simply absorbing all projectiles into its gelatinous form, with no signs of damage being present. It would also appear that there is little to prevent SCP-4397-1 from killing its targets, as tests have shown that SCP-4397-1 is capable of walking through and on water and is also capable of accessing any room so long as there is even a millimeter-large path into or out of the room. This gives the illusion that SCP-4397-1 is capable of phasing through solid objects, however, theoretically, SCP-4397-1 would be unable to enter or exit a vacuum-sealed chamber, although this has yet to be tested.
SCP-4397-1 will not attack anyone who isn't a target, but this doesn't mean bystanders aren't in danger. There is a high risk that anyone who gazes upon SCP-4397-1 will suffer extreme psychological trauma, possibly enough to outright kill witnesses by complete mental shut-down. As previously stated, SCP-4397-1 will never attack a non-target individual. The only exception to this rule so far identified is if one were to attack SCP-4397-1. SCP-4397-1 would then immediately redirect all focus on the attacker(s), driving at least 2 of its gelatinous appendages through the victim, causing it to rapidly transform into an instance of SCP-4397-2.
Instances of SCP-4397-2 seem to keep most, if not all, of their physical human features. Instead, they seem to "grow" the same black goo composing SCP-4397-1, which then arranges itself in a spiral formation all around SCP-4397-2's body. On the psychological side, instances of SCP-4397-2 lose all human psychological features, becoming feral and attacking anything that moves, except for SCP-4397-1 or other instances of SCP-4397-2. Unlike SCP-4397-1, instances of SCP-4397-2 do take damage and can be killed via conventional firearms, although they are quite tough and will take several shots to go down.
After SCP-4397-1 has killed all 4 of its targets, it will immediately revert back into SCP-4397, with all the black goo seemingly dematerializing, and all of SCP-4397's clothing, including his previously broken constraint, rematerializing as if nothing had happened. All of SCP-4397's physical and psychological features return, and SCP-4397 becomes docile once again, and ready to be recontained.
