Special Containment Procedures: 

SCP-999 is granted unrestricted movement within the facility, with the freedom to roam as it desires. However, it must return to its designated pen between 8 PM and 9 PM for sleeping, and during emergency lockdowns to ensure its safety. SCP-999 is not permitted outside its pen at night or beyond facility grounds at any time. The pen must be maintained in a clean condition, and its food replaced twice daily. Personnel are allowed inside SCP-999's holding area, provided they are not assigned to other tasks or are on break. Interactions with SCP-999 should be conducted in a calm, non-threatening manner, including play sessions when the entity appears bored.
Description:
SCP-999 manifests as a sizable, amorphous, gelatinous mass resembling translucent orange slime, weighing approximately 54 kg (120 lbs) with a consistency akin to peanut butter. The entity displays remarkable malleability, capable of altering its size and shape at will. When at rest, SCP-999 assumes a rounded, oblate dome form, measuring around 2 meters wide and 1 meter in height. Its surface comprises a thin, transparent membrane reminiscent of an animal cell, approximately 0.5 cm thick, and highly elastic, enabling SCP-999 to flatten parts of its body up to 2 cm thin. This surface exhibits hydrophobic properties, although SCP-999 can willingly absorb liquids (refer to Addendum SCP-999-A). The interior of SCP-999 is filled with a viscous orange substance of unknown composition, proficient at digesting organic matter with ease.

SCP-999 exhibits a temperament akin to a playful and affectionate dog. Upon approach, it reacts with overwhelming elation, slithering toward individuals and engaging in physical contact, often embracing them with pseudopods while nuzzling their faces with another. Throughout these interactions, SCP-999 emits high-pitched gurgling and cooing sounds. Notably, the surface of SCP-999 emanates a pleasant aroma, tailored to the individual it interacts with, ranging from scents such as chocolate, fresh laundry, bacon, roses, to Play-Doh™.

Direct contact with SCP-999's surface induces an immediate mild euphoria, intensifying with prolonged exposure and persisting after separation from the entity. SCP-999's favorite activity is "tickle-wrestling," involving enveloping a person from the neck down and tickling them, though it might not always cease immediately upon request. While accidental injuries can occur, SCP-999 has never demonstrated intentional harm, promptly retracting and quivering while emitting sounds resembling a whimpering dog, seemingly apologizing for unintended harm.

SCP-999 exhibits a particular affinity for individuals experiencing distress. Those suffering from conditions like severe depression or PTSD have reported notably improved outlooks on life after multiple interactions with SCP-999. Discussions regarding the potential development of antidepressants derived from SCP-999's slime are underway.

Beyond its playful nature, SCP-999 displays profound love for all animals, especially humans. It abstains from consuming meat and has demonstrated self-sacrificial behavior, exemplified by instances where it shielded individuals from harm, even taking a bullet intended for them (debates persist regarding its intellect; though its behavior is childlike, it seems to comprehend human speech and modern technology, including firearms). SCP-999's diet exclusively consists of candies and sweets, with favorites including M&M’s™ and Necco™ wafers. Its feeding methods resemble those of an amoeba.

Note: Detailed records of SCP-999's interactions are essential for further study into its empathetic and therapeutic qualities.