Master Yo is Yin and Yang's sensei as well as their father. He had taught the duo everything they know about Woofoo.
In his heyday, he was a hip and capable master of Woofoo. He had several arch-foes, such as Kraggler. Now a days, he's a lazy, grumpy old panda who prefers to spend his days doing absolutely nothing. He is also money grubbing and is a bit of a pervert. He can also be easily distracted by food. But whenever Ying and Yang needs him, he will be there for them whenever he can, whether it be teaching them Woo Foo arts or giving them advice. Although often when he tries to teach them something that they don't care about, they would just express it in a non-subtle manner which would annoy him. They sometimes show their immaturity by not respecting him at times be it because he is old or they just don't want to learn something that they don't care about. However, even the lesson that they don't want to learn would eventually come around to them and they would use it to best their enemies.
