Jiiza (ジーザ, Jīza) is a character that only appears in the Konjiki no Gash!! Gaiden: Friend as the antagonist of the side story.
Jiiza convinces Muumu that Zatch is a king who doesn't care about poor people. After that, he payed Muumu to steal the wand that Zatch has and gave it to Jiiza, thus, preventing Zatch from casting spells and allowing Jiiza to cast spells. Jiiza attacks Zatch with Bidyuron. He takes back the money from Muumu, kicks him, then, stomps on Muumu's house. After that, he uses Bidyuosen to kill Muumu but Zatch protects Muumu. Jiiza then uses his most powerful spell, Negurono Zoou Bidyun to kill Zatch and Muumu. In a desperate situation, there was nothing that Zatch could do since Jiiza has his spell-jamming wand, but miraculously, Kiyo Takamine from the Human World shouted "Bao Zakeruga," when he thought he had Zatch's red spellbook and in the Mamodo World, a Bao Zakeruga came out of Zatch's mouth, bypassing the spell-cancellation powers of his wand, and defeated Jiiza.