SCP-999 is permitted to move freely within the facility at its discretion. However, it must return to its enclosure either between 8 PM and 9 PM for rest or during emergency lockdowns for its safety. The subject is not allowed outside its enclosure during nighttime hours or beyond the facility grounds at any time. The pen should be maintained in a clean condition, with food

replenished twice daily.

All personnel are welcome to enter SCP-999's holding area, but only when they are not currently assigned to other tasks or are on break. SCP-999 is to be engaged with when it appears to be bored and interacted with using a calm and non-threatening demeanor.

SCP-999 is an amorphous, gelatinous mass with a translucent orange appearance, weighing approximately 54 kilograms (120 pounds). Its consistency is similar to peanut butter, and it has the ability to change its size and shape at will. When at rest, SCP-999 assumes a rounded, oblate dome shape, measuring roughly 2 meters in width and 1 meter in height. The surface of SCP-999 is covered by a thin, transparent, and highly elastic membrane, similar to an animal cell's, with a thickness of approximately 0.5 centimeters. This membrane is hydrophobic but can absorb liquids voluntarily (see Addendum SCP-999-A). The interior of SCP-999's body contains a viscous orange substance of unknown chemical composition, with the capability to digest organic materials.

SCP-999 exhibits a temperament characterized as playful and dog-like. When approached, it typically responds with overwhelming elation, slithering toward the nearest person and leaping upon them. SCP-999 engages in "hugging" with a pair of pseudopods and nuzzles the person's face with a third pseudopod while emitting high-pitched gurgling and cooing sounds. The surface of SCP-999 emits a pleasant odor that varies based on the individual it is interacting with, with recorded scents including chocolate, fresh laundry, bacon, roses, and Play-Doh™.

Merely touching SCP-999's surface induces an immediate mild euphoria, which intensifies with prolonged contact and persists after separation from the creature. SCP-999's favorite activity is "tickle-wrestling," often by enveloping a person from the neck down and tickling them, occasionally continuing even when asked to stop, although it ultimately complies with such requests. While injuries may occur, SCP-999 has never been found to deliberately harm others. It immediately withdraws and contracts into a quivering mass, emitting whimpering sounds similar to a distressed dog, seemingly "apologizing" for any accidental harm.

In addition to its playful behavior, SCP-999 displays affection toward all animals, particularly humans. It abstains from consuming meat and has even put its own life at risk to save others, such as leaping in front of a person to shield them from a bullet (SCP-999's intellect remains a subject of debate: while its behavior appears infantile, it seems to comprehend human speech and most modern technology, including firearms). SCP-999's diet consists exclusively of candy and sweets, with its preferred choices being M&M's™ and Necco™ wafers. Its method of consumption resembles that of an amoeba. The potential for manufacturing antidepressants from SCP-999's slime is currently under discussion.