Harpo's stage name was Harpo, his character being named the same as his stage name. His actual name was Adolph.
Groucho, Harpo, Chico, Zeppo, and Gummo
Aside
A single character play is called a monologue. It features a single actor speaking alone on stage.
Harpo Marx
balls
That is called a soliloquy, where a character speaks their thoughts aloud while alone on stage, or an aside, where a character speaks directly to the audience while the other characters on stage cannot hear them.
The plot stage that begins when the main character first faces trouble is called the "Rising Action." This stage involves the development of the conflict and the main character's initial responses to the challenges they encounter.
The stage Yankee.
A stage persona is a character or social role put on by an actor. Stage personas can be a completely fabricated character, or can be an exaggeration of the actor's own personality.
A character in literature, is the same as an actor on the theatre stage.
* understanding of the character
An actor (actor or actress) will perform a role as a character in a play on a theatre's stage.