Claus

"Dad. It's me. Claus. I told Lucas to come too, but he's been crying at Mom's grave all this time. Dad. I'm gonna leave this apple here. The core might be hard, but... The core... The core might be too hard to eat, but be SURE you eat it! I'm gonna get stronger. ...I'm gonna get so strong even Dragos won't stand a chance against me! Dad... I..."

— Claus Claus (クラウス, Klaus in the North American version of Brawl) is a major character in Mother 3. He is a boy from Tazmily Village, and the energetic twin of Lucas. Claus looks very similar to Lucas other than the different colors of his clothing and hair, though he is energetic and far more courageous than Lucas. He is last seen by the player lying motionless near the Drago Plateau, although the residents of Tazmily are never made aware of this.

Spoiler warning: Plot and/or ending details follow.

It is not explicitly stated that Claus is alive until the end of Chapter 8, where it is revealed he is being exploited for his ability to use the elusive PK Love by Porky Minch.

Masked Man
"...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. It's Master Porky's slave robot! It does whatever I say! It acts on my will alone. It's my double. It doesn't know anything about who you are! *cough* *cough*"

— Porky Minch

The Masked Man is a mysterious character who debuts during the final scene of the fifth chapter of Mother 3, he is the secondary antagonist of Mother 3. He is the only other person besides Lucas capable of removing the seven Needles. He attacks with lightning, a sword, an arm cannon and some PSI powers; he also has the ability to destroy PSI Shields and use mechanical wings to fly away. He also has a move that is able to instantly render Lucas's entire party unconscious with a lightning attack, meaning that only himself and Lucas (because of the Courage Badge that was revealed to be a Franklin Badge) remain in the battle. The attack is unavoidable.

Claus works for Porky Minch, the Pig King, as what he refers to as his "adorable little monster," and never says a word in the story. Though a pigmask states to Lucas (who thought he was the Masked Man since he answered his phone) that he sounded "kind of cheery", possibly signalling that the Masked Man can, in fact, talk, though in an emotionless tone. Surprisingly, he is the final boss, rather than Porky Minch himself. Because of this, Porky has been the penultimate boss in both games he has appeared in.

The Masked Man is in reality, Claus, who was apparently discovered near the Drago Plateau by the Pigmask Army. He was brought back to consciousness and turned into a human chimera. Although it is unknown whether or not he was dead, this is most likely true as the Magypsies sense no heart in him. During this time, King P used him as a loyal servant and gave to him near full command of the Pigmask Army. Still, during this time, Claus's sense of self and memories have been forgotten and pushed deep inside of him.

At the end of the final battle with the Masked Man, after realizing his true identity and revealing himself as Claus, he fires an intense bolt of lightning at Lucas, purposely reflecting it off of Lucas's Franklin Badge, causing himself mortal damage and ultimately killing himself.

The Masked Man has three battle themes. The first music is a variation of "Strong One", entitled "Strong One (Masked Man)". The latter musics are heard during each portion of the final battle against the Masked Man, and are titled "Battle Against the Masked Man" and "It is Finished", respectively. "It is Finished" is an eerie, sad rendition of "Mother 3 Love Theme". During the moments with Hinawa speaking, the song is called "Memory of Mother".