The Monkey King is a prankster, show-off, and overall maker of mayhem, dubbing himself the King of Comedy. He first appears as a puppet, but when brought to life, he stands about six feet tall and has a shaggy mane of hair. He is also a sorcerer, conducting spells through a wooden staff, but his magic is mainly used for comic value. (Whether or not anyone else finds it funny is not a priority to him.) Usually, he wears a green shirt with yellow trim, but he changes costumes to fit the mood. His origins are unknown, but in his introductory episode, his revival turns Jackie into a puppet, and when Jade asks for a way to set Jackie free, Monkey King replies, "One of us would have to be stuck in Dollsville, and I ain't never goin' back!"
He first appeared in I'll Be a Monkey's Puppet, when Jackie bought a monkey puppet for Jade to use in her upcoming ventriloquism act for the talent show at school. Looking more closely at it, he saw a rhyme on the back that read, "To free me of glitches and put you in stitches, this merry ape begs: Pull my leg." Doing so, he transformed into a puppet, and the doll became a real monkey. Monkey King runs out and causes havoc on the town, and Jade and Jackie (animated by the Rat talisman) attempt to stop him. They only succeed when Uncle swallows his pride and gets a book with information about the Monkey King from a rival antiques dealer, who was the one who sold the doll to Jackie. Jade is able to trick the Monkey King into pulling Jackie's leg, and when he does, the magic reverses, restoring Jackie to human form and the Monkey King to doll form.
The Monkey King is next seen in Monkey a Go-Go, when two construction workers are breaking down a wall and find the doll inside the concrete. One of them follows the rhyme and gets himself swapped to doll form. The first goal of the Monkey King is to get revenge on the Chans. He goes to the shop, "interrogating" Tohru into revealing that the others have gone to Hawaii. He catches up with them during their search for the monkey that bears the magic of the Monkey talisman. Jade gets away, but he corners Jackie and Uncle at the mercy of his scythe and Grim Reaper costume. Jackie manages to convince him to try a funnier revenge, so he hangs them on a spit to roast luau-style. However, his attention is soon diverted by Haiku, the monkey with the talisman's magic. The tourists are impressed by Haiku's transformations, laughing and cheering as he changes, so the Monkey King tries to steal the show. His efforts fail tremendously, and his rage at being out-performed by another monkey drives him to steal Haiku from the now-escaped Chans and take him to a volcanic crater which he will cause to erupt via magic. When Daolon Wong shows up, not only is he also more interested in Haiku than the Monkey King, he points out that the eruption spell has not worked. It turns out that one ingredient (three pounds of wood) is missing, and to add injury to insult, Daolon Wong curses the Monkey King back into puppet form (which also restores the construction worker). As the Chans and Haiku clash with Daolon Wong, the puppet is knocked into the crater, which completes the spell and sets off the eruption. Daolon Wong is sent skyward, and the others try to flee but are buried in the flow. They resurface completely unharmed, realizing that it's not lava, but actually cherry gelatin. The last view we have of the Monkey King is as the Chans look down into the crater, seeing the doll encased in his red prison.