Doctor Who equivalent

The Doctor Who equivalent of a situation, person, or concept is the closest parallel that can be found to it within the vast and expansive mythos of Doctor Who. Because Doctor Who is known to emboit all of reality, there is usually a Doctor Who equivalent (or DWE) for anything you can think of. This makes "What's the Doctor Who equivalent of ___?" or simply "DWE?" a great way of bringing up off-topic subjects in /who/, and one that has been exploited by many a shitposter during the hiatus period.