A cute, but adult book about a castle, called the dungeon which is ruled by a bird, who is called the keeper. The dungeon is basically a business, which sole purpose is to trick warriors, wizards, etc to come be killed. Then, the keeper steals their money. Fighting for the dungeon, is Marvin, the vegetarian dragon and Herbert, the duck, and the duke of Craftiwich. They are the main characters throughout most of the books. I personally love these books, and I think anyone would love them :)
A. L. I. E. N., by Louis Trondhiem; The Rabbi's Cat, by Joann Sfar; Sardine in Outer Space, by Joann sfar and various artists.
I would recommend these books the anyone who likes quirky, adventure stories.