|“||Huh? That monster's name is Claus? Its name was Claus?! That almost sounds like a person's name! But now it's my robot. Not even a fragment of life remains inside it.||„|
|~ Porky, after realizing the monster he controlled was Claus|
Claus, also known as the Masked Man, is the secondary antagonist of Mother 3. He is the "commander" of the Pigmask Army, the son of Flint and Hinawa, and the older twin brother of the game's protagonist, Lucas. After being brainwashed by Porky Minch, he became the commander of the Pigmask Army when he tried to avenge his mother, Hinawa.
Before being brainwashed, Claus was a kind and positive child. He loved his family very much; it was when his mother, Hinawa, was killed by a Drago, Claus became angry and tried killing the Drago that killed his mother, going missing from Tazmilly Village.
After being brainwashed, Claus became a chimera full of hatred and resent towards the people who are against Porky, including his own family (his brother Lucas, and his father Flint).
Before being brainwashed, Claus wore clothes that are similar to his brother's; with opposite colors: cyan and yellow. Unlike Lucas, who is blonde, Claus has red hair in a similar style to Lucas'. He wears orange pants, white socks, cyan-white shoes.
After he was brainwashed by Porky, Claus appears to have become more pale and wears an entirely different uniform. He wears a black-gray coat resembling a fur collar bomber jacket with a belt around his waist, orange trousers, a pair of white gloves and black-gray boots. He wears a large gray helmet which obscures his eyes, with a shadow from the helmet hiding his left eye, while a gray eye-piece covers up his right. Due to his cyborg transformation, Claus uses a jetpack in the shape of wings which he can simply turn on at his own will, while his right arm frequently uses an arm cannon with tubing attached to either the jetpack or his own back itself. Whether the arm cannon is detachable or if Claus' right arm is actually cybernetic, in which it can transform into an arm cannon, is unclear.
Claus was originally a kind child, and was positive like his twin brother, Lucas. But then, after Claus' mother, Hinawa, was killed by a Drago, he leaves Tazmilly Village and ventures into the canyons to find and kill the Drago in order to avenge his mother's death. When Claus' father, Flint, hears of this, he leaves to look for Claus. He encounters and defeats the mechanically reconstructed Drago that killed his wife, but Claus is nowhere to be found. He was presumed dead.
In actuality, Claus was beaten within an inch of his life when he was found, captured, and killed by Porky and his Pigmask Army. Porky's ultimate goal was to have the seven Needles pulled to have the world "reborn" in his own image, but he did not possess the power to pull them. Porky saw the potential in Claus, and had him killed and reconstructed with robotic attachments, burying his memories deep inside of him. Breaking his will and his mind, Porky turned Claus into the commander of the Pigmask Army. After being brainwashed, Claus was no longer an innocent and positive child. He lost all the good memories he had in his mind.
The sleeping dragon below the Nowhere Islands would awaken and destroy the world if the seven Needles are pulled. The world would then be 'reborn' based on the heart of the person who pulled them. If a man with good intentions pulled the needles, the world would become a good place. Likewise, if an evil man pulled the Needles, the world would descend into chaos.
Claus was set to work on pulling the Needles on Porky's behalf, but it would seem that Claus had neither good nor evil intentions, as the Magypsies, guardians of the Needles, noted that the puller seemed to have no heart.
Lucas was the only other person capable of pulling the Needles, and he hurried to pull them before Claus. After Porky was defeated, Lucas encounters Claus, who is about to pull the final Needle. Claus fires a bolt of electricity, knocking his friends unconscious, but leaving Lucas unharmed because of his Franklin Badge.
Throughout the battle, Lucas is unable to attack Claus, since Claus was his brother. Claus unrelentingly assaults him with his sword and arm cannon. Hinawa's voice calls out to Claus, urging him to end the battle. This initially does not phase him and later Flint who intervenes in the fight but also fails reach his son, but as Hinawa's voice continues throughout the fight, he begins to be overcome by his long-thought-gone emotions. In the end, he takes off his mask and fires an immense bolt of lightning, which is deflected by Lucas' Franklin Badge, essentially killing himself. Though mortally wounded he had enough strength to share his final moments with his brother, he apologizes and thanks Lucas before claiming to "go to that place Mom is" but assures him that they will meet again before taking his final breath.
- Claus' name is an intentional anagram of "Lucas".