Identified by their namesake pitch black matte eyes, without a shine or texture. No adults are with them, they're noted for having a very adultlike manner of speaking, and like vampires, they have sinister auras and ask permission to enter your territory.
Starts off with, "hey mister/miss, I need a ride/Can I use your phone/I'm lost/Can I use your bathroom". The person they're asking usually gets a huge hunch to slam the door in their face, or just floor it out of there.
I think these stories came out around 2008? Some say it was some dumb viral marketing campaign like "have you seen this """"man"""" ", for some horror movie that never got made. IDK.