Claus is a character in the Game Boy Advance video game Mother 3. He is the slightly older twin of the game's protagonist Lucas, and is easily more excitable than his younger brother. When Flint looks for him near the Drago's cave, he finds only his shoe. While the other people of the town figure he's dead, Flint looks for him every day afterwards. After this, his whereabouts are unknown until the very end of the game, where it's discovered, much to the horror of Lucas, that Claus is the commander of the Pig Mask Army.
During the portion of the game when you do not yet know that he is Claus, he is referred to as "The Masked Man."
Claus' name is an anagram for "Lucas".
While Claus himself does not appear in Super Smash Bros. Brawl, when changing Lucas' color, he can appear with a teal and yellow striped shirt, orange shorts, and brown-red hair, resembling Claus as a child.
Claus, as a child, also appears as a sticker in Super Smash Bros. Brawl and and he is appear in SSB series Lucas's color variation.