Inu Daruma Brothers are mascots of Dog Drug Reinforcement arcade game appeared in Episode 6 that Kyouko was seen playing. They're not witches, and the card is put up on the official website as an easter egg.
イヌダルマブラザーズ。 大人気ダンスゲーム「Dog Drug Reinforcement.」のマスコットキャラクター。かつては南米で覆面レスラーとして活躍していたが試合中マットへ叩き付けられた瞬間に感じた地球の裏側からのビートに導かれて来日し ダンスシーンへと飛び込んだ。らしい。 ちなみに魔女ではないし、魔女とは何の関係もない。
Inu Daruma Brothers
IDB at their arcade game.
Inu Daruma Brothers. Mascots of Dog Drug Reinforcement. Previously were masked wrestlers from South America, whose beating on the mat are said to have resounded to the opposite side of the world, and thus became hits in the Japanese dance scene. Not witches, and aren't related to witches in any way.
Puella Magi Madoka Magica Official Guidebook "You Are Not Alone"