Shadow people are the most seen entity among witnesses. The jury is still out as to what exactly they are. Some believe they are another way for ghosts to manifest or demonic in nature. They've even been linked to time travel. A few common types:
Human Shaped - a shadow people type that take on the form of human (mostly male) lacking specific characteristics like eyes, nose and mouth. They tend to flee if you notice them.
Black Smoke or Mist - black smoke-like or mist type of shadow people. Possibly intelligent.
Shadow Animals - basically like the human shaped but in animal form, about the size of a rabbit. Not as common as other types.
Red Eyed Shadow - this type of most often associated with evil. A shadow person in human form with no specific characteristics except for bright glowing red eyes. Some people have even described them with yellow eyes.
We may never know the true nature of these beings. They may be real or just our imaginations running rapid. Demonic or guardian angels. No matter what they are, let your intuition be your guide.
If you have an experience you would like to share, send it to The Official Shadow People Archives.