Also known as: クラウス
Claus is the older, energetic twin brother of Lucas (Mother 3) in Mother 3. He is characterized as being braver than his younger brother. An alternate costume for Lucas in Super Smash Bros. resembles him.
After Hinawa's death, he goes off to try and kill the monster who did it, but dies in the process. He's resurrected as the Masked Man (Mother 3) by the Pigmask Army and has his memories suppressed. Lucas fights him as the final boss of the game.