Mason Brady

Mason Brady, also known as The Night Howler and Dr. Maniac, is the protagonist of the eleventh book in the Goosebumps SlappyWorld book series, They Call Me the Night Howler!

History
Mason Brady is an avid comic book fan, with one of his favorites being The Night Howler, a superhero that can hide in the shadows and capture foes in his cloak. One day, while visiting the superhero museum with his parents and sister Stella, Mason runs into the real Night Howler who tells Mason that he's quitting the superhero business. He's tired of fighting supervillains as well as constantly failing in defeating Dr. Maniac. He gives Mason the costume and the mantle of being the Night Howler. Mason is thrilled and takes on the job, but is told to never reveal his identity to anyone or he'll lose the powers of the costume.

Mason takes on the job, and at first seems to handle things well, defeating a supervillain known as the Quitter. However, he's soon bested by a supervillain named Blue Strawberry who constantly bests him at every encounter. Eventually Mason begins to suspect that Blue Strawberry is really Stella after seeing the costume in her room, but when he encounters Blue Strawberry, he unmasks her, only to reveal some other woman's face under the mask. Mason soon learns that Stella's costume was a Halloween costume. Soon Dr. Maniac shows up in his house. Mason tries to stop him, but due to revealing his identity to Stella, his powers no longer work and Dr. Maniac escapes.

Mason returns to the superhero museum with the Night Howler costume to donate it, only to run into Dr. Maniac. He tells Mason that he's quitting the supervillain business and that he'll give Mason the costume and mantle of Dr. Maniac, which Mason accepts.

Personality
Mason Brady is a kid who really loves comic books and superheroes. He is usually easygoing, but gets easily annoyed by his sister Stella, mainly because she wants to do whatever he does, including taking up an interest in superheroes. While at first on the side of good, after failing as the Night Howler, he ultimately accepts a life of evil as the new Dr. Maniac.

Powers
As the Night Howler, Mason gains the ability to cloak himself in the shadows. He also has the power to cast a large shadow over his foes which traps them in place. The only downside to these powers is that if Mason reveals his identity to anyone, he loses those powers forever.