SCP-531 are brass statues depicting stylized felines. The cats are in a seated posture, looking forward with ears raised in what is usually described as an 'attentive' expression. Each cat is 74.2 cm tall and is solid metal weighing 451.7 kilograms. Their eyes are inset with what appear to be polished tiger-eye stones that give an impression of luminescence, though they do not directly emit visible light.

When in a pairs facing each other, they cause a psychic suggestion that it is impossible to cross between them. If the line of sight between the two statues is broken, observers will be compelled to meet the gaze of one of the orphaned statues. Once their eyes meet it becomes extremely difficult to look away. The trapped individual will feel a mental pressure forcing them to crouch down so that his eyes are level with the statue's. After several minutes in this pose the subject's body begins to slowly stiffen and become heavier as a transmutation effect takes hold, converting the subject into a duplicate SCP-531 over the course of one hour. The subject remains aware throughout the process but will remain unable to break the statue's gaze. The duplicate is an exact copy and produces the same effects as the original SCP-531 statues.

To summarize, SCP-531 are statues of cats that cause petrification and twinning.