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.