Sadie is the guard leading the four Impel Down's tormenting beasts: Minotaurs, Minokoala, Minorhinoceros and Minozebra. To keep them calm, and be obedient to her orders, Sadie uses a long and dangerous whip called "Akamamuchi". With this whip, she is also responsible for punishing prisoners of Impel Down and satisfy her sadistic needs.
Koufun No Geki: AkamamuchiKanji: 興奮の檄 赤魔鞭
Translation: Arousal Manifesto: Red Demon Whip
Drawing his whip, Sadie begins to lash out at whoever is around. With it, she also seeks to hang his victims. According to her, it's able to decapitate a person.