Special Containment Procedures: Temporary foundations have been built in every known location of SCP-4219 and agents are sent to keep surveillance on the area. In no circumstances should SCP-4219 be allowed into populated areas and in a similar vein, no living creature can be allowed into the infected environment with SCP-4219. A perimeter should be built around the infected area with an agent surveying the border during the night. Cameras are to be used during the day. Should one of SCP-4219 escape the area the agent on guard will be demoted, sent to a new facility and replaced. Search Agents trained in tracking down SCP-4219 will search the surrounding area. If SCP-4219 has infected an innocent do not hesitate to shoot on sight. SCP-4219 must either be recaptured or, if necessary, terminated. If anyone should ask what the barrier is for the guard on duty should tell them it is a radioactive chemical leak, and if anyone tries to force their way past the barrier they should be detained and questioned.
Description: SCP-4219 is an amphibious aquatic parasite. It looks to be in the Actinopterygii family but we now know this not to be the case. The head of SCP-4219 is about 12 inches in diameter with two foot long appendages growing out of the back. SCP-4219 moves at an estimated 35 mph speed and uses small crevices or holes to hide in if nearby a potential host. The anomaly has large bulbous eyes that stick off the side of its head. It has a larger jaw and rows of needle-like teeth. The head has seven long appendages sticking out the back that it uses to swim quickly in water and move swiftly across the land. Each appendage is lined with incredibly strong suckers that it uses to attach to its host, or in some circumstances to climb surface objects such as the barriers around the infected area. SCP-4219 have been discovered in both freshwater ponds and saltwater oceans. Any sort of bright light causes the skin of the anomaly to dry up and crumble, killing SCP-4219 almost instantly. SCP-4219 can sustain life outside of fresh and/or salt water for what's theorized to be an unlimited amount of time. The longest we have known one of SCP-4219 to be on land is three months, seven days, and twelve hours before an unfortunate accident that allowed the anomaly to escape, where shortly after it got itself killed by artificial light.
SCP-4219 are carnivorous and have been seen to consume any meat they find, living or deceased. The main goal of SCP-4219 is to attach itself to a host and use them to consume food. SCP-4219 will climb onto any living creature and use its suckers to attach to the host. Through the suckers, it injects a chemical compound into the host that kills their mind, allowing SCP-4219 to take control. If SCP-4219 is killed or removed the host remains brain dead. The preferred hosts of SCP-4219 are humans or other bipedal creatures, for their ability to use their arms to grab the meat of its victim and feed it directly to SCP-4219. SCP-4219 has used humans to kill and consume friends, family, and pets of the host.
SCP-4219 was first believed to be an undiscovered aquatic species but further research led us to the conclusion that SCP-4219 did not exist before 1957. The first appearance was after the first failed attempt at randomized interdimensional travel by [REDACTED]. The current theory is that SCP-4219 is a creature from Dimension X-34-F, the dimension [REDACTED] was unknowingly trying to open a gateway to.
How SCP-4219 reproduces is currently unknown along with the number of existing locations. Permanent containment of SCP-4219 is impossible for the time being but temporary barriers are built trying to keep the attacks to a minimum.
