The Kappa Tengu are simply a stylized version of the Japanese demon known as the "Kappa". The term "Tengu" was used as a generic term for "Japanese demons" in The Lost Episodes, and thus, was affixed to the character's name.
The Kappa Tengu are simply a stylized version of the Japanese demon known as the "Kappa". The term "Tengu" was used as a generic term for "Japanese demons" in The Lost Episodes, and thus, was affixed to the character's name.