The phrase "Who in the dickens are you?" is a colloquial and slightly humorous way of asking someone about their identity when surprised or confused.

It's akin to saying "Who on earth are you?" or "Who in the world are you?" The term "dickens" in this context serves as a mild expletive used to add emphasis to the question, without being offensive.

The origin of this phrase can be traced back to the works of Charles Dickens, a renowned 19th-century English novelist. However, its usage has evolved over time, and it's no longer directly connected to the author. Instead, it's a playful and informal way of expressing curiosity or astonishment when encountering someone unexpectedly. Imagine walking into a room and finding someone you didn't expect to see. You might blurt out, "Who in the dickens are you?" It's a lighthearted expression that conveys both surprise and a touch of confusion. The use of "dickens" adds a bit of color to the question, making it sound more intriguing.

Overall, the phrase captures a moment of being taken aback and wanting to know more about the person who has caught you off guard.