These two authors are quite the pair. They go under the aliases of a rabbit and bird, and when asked who or what "Team GuJiu" (their team name) means, they respond with the answer: "Because HanaHana is a bird who goes 'gu gu', and Bixi is a rabbit that goes 'jiu jiu'."
They work on and publish their own manga as a pair, with their main (only?) project being "Good Luck, Demon King!" and they sometimes draw their bird and rabbit aliases into the manga itself. If you want some more information on this chinese mangaka duo, visit their blog using the link provided below. They even have quite a few artistic spoilers for their series for those who cant read the blog itself.