The term 'alter ego, fictional' can be summarized as the crossword solutions Hyde (4 letters). An alter ego is a second self, which is often distinct from a person's normal or true original personality. In fiction, an alter ego is often portrayed as a character who has a different personality than the protagonist, and is sometimes used to explore a different side of the protagonist's character. The most famous example of an alter ego in fiction is Dr. Jekyll and Mr. Hyde, where Dr. Jekyll is the protagonist's original personality, and Mr. Hyde is his darker alter ego.