Black Mokona or "Larg" isn’t quite as enthusiastic and energetic as White Mokona, but nevertheless a teaser, which results in a reaction from Watanuki similar to Kurogane's. As Soel was made especially for Sakura, Larg was made for Watanuki.

Little is known about Larg, except that it is able to see ghosts, something the White Mokona, Soel, cannot do, and that its main purpose is to stay in contact with Soel, so that Yuuko can know where the group is and assist them if necessary. Also, Black Mokona is used for teleporting things to the White Mokona and vice-versa. It is done by swallowing by one of them and spitting them out by other. Yuuko has also remarked that of the two Mokona, the red earring on the white one possesses the ability to enhance magical power while the blue earring on black one has the ability to seal magical power.

Like Yuuko, Black Mokona loves to drink sake. The name Larg comes from the rune Laguz meaning water. Larg is officially "male".

In Horitsuba Gakuen, he is a twin of girl Mokona.