The Fallible Fiend

is the first volume of the japanese translation of The Fallible Fiend novel series, written by LS Decamp and Illustrated by Ayumi Konomichi. It was released under the Dengeki Bunko Imprint in April 1997.

Synopsis
Anyway, aside from the details, the devil comes to the apprentice. Zudom, who looks like a dragon and a catfish, is a demon who lives in the land of Nin, but one day he is suddenly ordered to serve as an apprentice in the human world. He's a terrific Zudom to look at, but he's actually an intelligent and straightforward personality. If the wizard Mardivis tells you to eat and kill anyone who comes in while you are away, you will do so. Even if it is Mardivis's only disciple. Adventure slapstick fantasy caused by the stupid devil Zudom. As a result of Tetsuya Tanaka's leisurely and enjoyable translation, this is what happened. Is this really okay?

(source: Amazon JP - Translated)