Someone who seems to have just popped out of nowhere, and no one can properly see their face as it always looks like it is being blurred, as if something trying to hide his or her identity. There are no records of their history whatsoever as if they never existed here in this world in the first place until now. A possible anomaly that distorts the flow of time and space with him/her just existing, tho, only by a small margin, not causing a threat to the timeline whatsoever.