The Black Mokona can be found where you least expect him.
History
white and black Mokona are copies of the original Mokona, who appears in Magic Knight Rayearth (another Clamp series). The two were created by Y?ko Ichihara and Clow Reed (who appear to be aware of the existence of Sakura Kinomoto and all of the events in her world). One day, Y?ko and Clow encountered the original Mokona, who was traveling through different worlds, and Mokona provided Y?ko and Clow with the knowledge of alternate dimensions. After learning that one day a Sakura and Syaoran from an alternate world would come to their world to ask for help, Y?ko and Clow created the two Mokona, basing them on the original but with slight differences, such as difference in size and the ability to talk (whereas the original Mokona would only say "Puu!"). Each Mokona was also given an earring which matched the color of the gem on its forehead, the blue earring seals magic power while the red earring boosts magic power.
HE is a copie of this Mokona.
Mokona is a mischievous, nonsensical rabbit-like creature with a striking similarity to a white manju bun, with a red gem in his forehead above his eyes. From this gem he can produce a tent for the girls to sleep in, food, and other necessary supplies. He is unable to speak, aside from repeating the sound "puu", although Hikaru seems to be somewhat able to understand him. In the manga, Mokona is revealed to be the Creator of the Earth, Cephiro and the other planets, as well as the laws for each planet. In the ending of the second series, Mokona and the rest of the Mashin announce that they will be traveling to other dimensions.
the mokona's were given to Gemini after Y?ko Ichihara retired from beinhg the dimesional witch. (Gemini coming soon)