Yin Yang Yo!

Yin: A student of Master Yo and the younger twin sister of Yang. Yin is intelligent, cute, feminine, and sassy.
Yang: A student of Master Yo and the older twin brother of Yin. Yang is a courageous yet negligent and hasty character.
Master Yo: The skillful master of ancient martial arts known as Woo Foo. Master Yo is often portrayed as arrogant, stubborn, and indifferent.
The Night Master: Billed as a "Dark Overlord in an Evil Class All By Himself", the Night Master is a very powerful and dangerous foe who was responsible for the near extinction of Woo Foo.
Lina: Yin's friend and Yang's crush. Lina is a tomboyish girl who is often seen hanging out with Yin and Yang.
Chung Pow Kitties: A trio of evil cats who are often seen as the Night Master's henchmen. The Chung Pow Kitties are skilled in martial arts and often use their powers for evil.
Carl the Evil Cockroach Wizard: A cockroach wizard who is often seen as the Night Master's henchman. Carl is a bumbling villain who is often more interested in eating than in evil.
Eradicus: The original and reborn Night Master. Eradicus is a powerful and evil being who is bent on destroying Yin and Yang.
Edna: Master Yo's romantic interest and the mother of Carl the Evil Cockroach Wizard. Edna is a kind-hearted woman who is often put off by Master Yo's arrogant and stubborn personality.
Possum Panda: Master Yo's alter-ego and a crime-fighting vigilante. Possum Panda is a parody of Batman and is often seen fighting crime in Master Yo's place.