ADVISORY TO FOUNDATION PERSONNEL
Requests to transfer to SCP-7898 are to be approved by Dr. Belfair. Transfer requests lacking proper authorization will not be added to the wait list.
CURRENT TRANSFER WAIT TIME: 3 years, 45 days
Special Containment Procedures: All 122 existing instances of SCP-7898 are currently held in a specialized atrium habitat in Site-109. Upper atrium windows of SCP-7898’s containment are to be uncovered for a minimum of 5 hours per day, adjusted on overcast days to provide SCP-7898 sufficient sunlight. Atrium windows are to be covered and the containment area filled with aerosol sedative during Blood Sun cycles. Any new instances of SCP-7898 and SCP-7898-1 are to be incinerated. The town of Fields Spring has been demolished and its existence expunged from public record.

SCP-7898-1 instance while dormant
Description: SCP-7898 is an arachnoid parasitic creature that inhabits human bodies for locomotive and reproductive purposes. SCP-7898 nest in dark, dry, enclosed spaces, most commonly inside the walls and crawlspaces of houses, and subsist on sunlight1 in a process similar to photosynthesis.
SCP-7898-1 instances are the full human bodies used by SCP-7898 for locomotion. SCP-7898-1 instances retain the ability to move and speak similarly to non-anomalous humans, but lack many bodily functions including eating, drinking, and waste expulsion. SCP-7898-1 instances also seem incapable of experiencing or expressing negative emotions, even in response to physical pain or megadental events.
SCP-7898 themselves measure between 15-25cm in length and typically weigh between 4-6kg2, depending on the age of the host, with six legs visually similar to a spider3. While any of SCP-7898’s original sensory organs are not visible outside the carapace, observation suggests that SCP-7898 navigates using smell and hearing when not attached to an SCP-7898-1 instance.
SCP-7898 was originally discovered in the town of Fields Spring4. There were no survivors.
Addendum 1 - Life Cycle of SCP-7898
Based on discoveries from both Field Springs and Foundation experimentation, the observed life cycle of SCP-7898 is as follows.
Phase 1: A mature instance of SCP-7898 will hide within the hollow walls of a building, most frequently a house, where it waits for a suitable host.
Phase 2: The instance will break through the drywall from within, grab the head of the host, and use a sharp appendage to implant an egg in the host's ear.
Phase 3: The host experiences mental fog, manic episodes, head/neck pain, and neck muscle weakness.
Phase 4: The host feels compelled to keep their head inside small, dark places, such as under blankets or in containers.
Phase 5: The host will force their own head through a wall, life signs cease.
Phase 6: The host's head rips off at the neck and arachnoid appendages of a fully mature SCP-7898 instance emerge from the mouth, ears, and throat.

SCP-7898 instance
Experiment Log
Experiment | Result |
Extracting SCP-7898 egg from host after implantation | Failure, host subject experienced immediate brain death |
Denial of a suitable nesting space to a growing SCP-7898 instance | Subject attempts to break head through concrete wall, dies |
Consumption of SCP-7898-1 instance | Subject becomes severely ill and expires, SCP-7898 reclassified to Class W74 Inedible Corpse |
SCP-7898-1 instance taken outside during a Rending event | SCP-7898-1 instance increases dramatically in physical strength, infects 2 accompanying personnel before being terminated. Instance remains incinerated |
Exposure to unfiltered fresh water5 | No notable effect beyond ordinary chemical burns |
Exposure to untreated seawater from the Panarctic Ocean6 | Integrates with the water, becomes transmissible through any physical contact with the water as evident by multiple cases among attending staff. Water sample destroyed |
Note: This anomaly has been marked as a primary candidate for the developing Salvation Initiative, a program to temporarily reassign recently traumatized researchers to safer, less stressful anomalies, due to its low staff death rate and similarity to mundane and ordinary phenomena.