It's appearance is like a pale girl aged between 16-20, although can change. It can appear solid but also can appear translucent, glowing with a faint blue aura, leading many before capture to think it is a ghost.
Exposure to it or even being close in the next room over can cause varied effects. The subject will appear to see a lost loved one or loved one, be it family or close friend. This begin with the first exposure and extend for several days. The hallucination will appear, look at the subject and then run away, the subject often giving chase for several minutes. The subject will then loose sight and come to his/her senses.
After several appearances the hallucination will face the subject and say a simple sentence, often with devastating mental effect on the subject, for example: 'You could have saved me' or 'I never loved you' depending on the subject, then disappear. After that the subject will become obsessed with finding the SCP and when they do, will kill themselves in sight of it.
The SCP can change its appearance in the view of the subject to the hallucination while appearing the same to others. Also it can float through space regardless of its composition, be it water or solid matter, leading many to speculate it is partly or mostly contained in an extra dimension.