|Status||Imprisoned in a Mask|
|Mask Wearer||Hak Foo|
|Previous Affiliation||Feudal Japan|
|Mask Debut||Season 4 Episode 8|
|Debut/Closing||Season 4 Episode 13|
He is dark yellow, has two big eyebrows and a small mustache. He also has a single horn on top of his head.
In The Shadow Eaters, Mosugurīn's mask was found in a swamp. Hak Foo successfully put on the mask and summoned his Shadowkhan only to be disappointed by their size. Later, he learned from Tarakudo that his Mini Khan are just as deadly as the others. At the end of the episode, Jackie used Uncle's blowfish and removed the mask.
In Ninja Twilight, after the nine masks was joined together, all of the Oni generals were freed and tried to destroy the world. Mosugurīn was walking with Oni Kuro to one of the four corners of the earth. They were briefly defeated by Viper but Tarakudo managed to capture her. After Jade put Tarakudo's mask on his face, all the Oni and Shadowkhan were imprisoned within.