A disguise can be anything which conceals or changes a person's physical appearance, including a wig, glasses, makeup, fake moustache, costume or other items. Camouflage is a type of disguise for people, animals and objects. Hats, glasses, changes in hair style or wigs, plastic surgery, and make-up are also used.
Disguises can be used by criminals and secret agents seeking to avoid identification. A person working for an agency trying to get information might go 'undercover' to get information without being recognised by the public; a celebrity may go 'incognito' in order to avoid unwelcome press attention. In comic books and films, disguises are often used by superheroes, and in science fiction they may be used by aliens. Dressing up in costumes is a Halloween tradition.
In comic books and superhero stories, disguises are used to hide secret identities and keep special powers secret from ordinary people. For example, Superman passes himself off as Clark Kent, and Spider-Man disguises himself in a costume so that he cannot be recognized as Peter Parker.
Sherlock Holmes often disguised himself as someone else to avoid being recognized. Examples include dressing as a peddler in order to avoid being spotted on the moor so that he could get his investigative work done in The Hound of the Baskervilles, or as an Indian sailor so that he could speak with Professor Moriarty about his evil plan in Sherlock Holmes and the Secret Weapon.
In science fiction, aliens often take on a human appearance wearing "human suits" as a disguise.
In epic poetry, Odysseus uses the disguise of a beggar to test his family's and servants' loyalty upon his return from a 10-year voyage.
Disguise is sometimes used in criminal activity and in spying, and is a common trend in detective fiction and in spy stories. Arsene Lupin is feared in Maurice Leblanc's stories because of his extreme ability to disguise himself; this is a trademark of Lupin.
The Clay Camel, one of Mandrake the Magician's foes, is considered the Master of the Disguise, because he is able to mimic anyone and can change his appearance in seconds.