Here's English language publisher NBM's page on the series).
Fortunately it stands on its own as a good place to start, and turned out to be a really fun fantasy adventure. Fast moving, funny at times, with a lot of surprises as we follow an old and blind dragon warrior named Marvin going to his death, gaining companions like a seeing-eye bat and a young warrior rabbit also named Marvin (in honour of the dragon Marvin's younger exploits). Along the way they run afoul of an overlord duck named Herbert, a former companion of Marvin. And all that only scratches the surface of some of the weird concepts and characters that populate the book. And somehow it all works, with clear storytelling, fun scripting and some amazing character and setting designs.
I'm definitely going to have to read some more of this series, and see if I can figure out what exactly is going on. There's a lot of intriguing stuff in here.