barker

noun

• Someone or something who barks.

  "My neighbor's dog is a constant barker that keeps me awake at night."

• A person employed to solicit customers by calling out to passersby, e.g. at a carnival.

  "Bob had amassed a considerable stockpile of double entendres from his days working as a barker for a strip joint."

• A shelf-talker.
• A video game mode where the action is demonstrated to entice someone to play the game.

  "The barker mode of the arcade video game convinced the teenager to spend a quarter."

• A pistol.
• The spotted redshank.