"Who ___?"

ELSE

Think of a common phrase used when asking if there are other people or options besides the ones already mentioned.

The clue "Who ___?" is a common phrase used when asking if there’s another person involved, like "Who else?" The answer "ELSE" fits because it completes the phrase naturally, meaning "in addition to someone already mentioned." It’s a straightforward fill-in-the-blank where the missing word is a simple, everyday term. No wordplay or tricks—just a direct way to finish a familiar question.