It seems Karl Lagerfeld is the hero of his own “Devil Wears Prada” type book. One of the legendary designer’s ex-assistants, 37-year-old Arnaud Maillard, wrote a tell-all about his personal experience working for Lagerfeld after he was fired in 2005.  Lagerfeld is characterized as extremely fickle and narcissistic by Maillard.
As of yet, the book has only been released in France with upcoming plans for a Germany launch. However Maillard discussed the book with Germany’s Spiegel, and a number of interesting tidbits were revealed.
Maillard maintains that he has the utmost respect for the Kaiser, but that he wanted to reveal another side of the famed designer noting that he is “an unbelievable narcissist. He needs an eternity to get ready in the morning. He takes photos of himself at every photo shoot and puts them everywhere. He surrounds himself with a kind of royal court, and nobody disagrees with him. Wherever he goes, there is Pepsi-Cola in a Baccarat crystal glass waiting for him and it gets replaced every 30 minutes. It’s like the 18th century.”
Maillard goes on to say that Lagerfeld uses the world’s most expensive body cream from La Prairie twice a day (even between his toes), and that the designer is very fickle and “dumps people at the drop of a dime.” 
Insight into Lagerfeld’s H&M collaboration were also revealed, with Maillard telling the Spiegel reporter that he remembers how the designer sent him the first sketches for the H&M collection under extreme time pressure, and that the Lagerfeld team worked day and night for three months on the collection, but never saw any extra pay. “I can remember well the two half-days that Karl worked on the drafts," he says, "Then he got millions from the Swedes.” 
As it is to be expected, Lagerfeld tried to stop the publishing of the book, but was unsuccessful in his attempt.