Watcher

Drawing of symbol that Gemma identifies on the Watcher's hand

The Watcher was first seen in the video Exploring The Motel and subsequently in Breakfast In Bed and is referred to as "The man in the suit" until Gemma correctly identifies him as a Watcher in A Watcher. Watchers operate like an order of knights, and Gemma believes that a modern version of the Watchers are part of The Order.

Wikipeida shows several uses of the term watcher. Of particular interest is Grigori which according to Wikipedia "are a group of fallen angels told of in Biblical apocrypha who mated with mortal women, giving rise to a race of giants known as the Nephilim. Also known as "Watchers" (from Greek egrḗgoroi), the Grigori appear in the books of Enoch and Jubilees".