Old Giao Tze. He's the assistant of Hooo the Black Magician. Since Hooo keeps reading on how to bring about disaster, Giao is the one who actually takes over the practical aspect of the mission.
He would have destroyed everything in Phyci-Digi Land using Hooo's experiments, but he's too old for it, plus he's struggling with his rheumatism. Basically he's just grumpy and complaining.