Answer:

phantom

Answer	Crossword Clue
PHANTOM	"The Music of the Night" singer
PHANTOM	Apparition
PHANTOM	Illusory

PHANTOM	Specter
PHANTOM	"Opera" guy
PHANTOM	Scooby-Doo encounter
PHANTOM	Superhero
PHANTOM	Opera villain?
PHANTOM	"The .. of the Opera"
PHANTOM	Mirage
PHANTOM	Vision.

PHANTOM	Ghost story character.
PHANTOM	Revenant.
PHANTOM	Wraith.
PHANTOM	Specter.
PHANTOM	"The ... of the Opera," Chaney film
PHANTOM	Imaginary
PHANTOM	Not real
PHANTOM	Not really there

PHANTOM	Long-running Broadway musical, familiarly
PHANTOM	Unreal
PHANTOM	Universal Studios role of 1925
PHANTOM	Stray Cat drummer Slim Jim
PHANTOM	Andrew Lloyd Webber title villain
PHANTOM	Opera interrupter of note
PHANTOM	Musical's masked man
PHANTOM	Fictitious