The finest of the Mohammed caricatures, I think, was Cabu's from 2006, in the wake of the Jyllands-Posten riots, which showed a little sympathy for the old Prophet overwhelmed by intégristes or fundamentalists and doing a double facepalm: "It's tough being loved by cons..." (the word, etymologically referring to the vagina, has much less force than English "cunt" and is more of an equivalent to "asshole").
On the whole, though, the worst thing for posterity about the murders of the Charlie Hebdo staff is that these heroes may be remembered for what wasn't their best work, the relatively crude and satirically unpointed drawings of 2011 and 2012 showing the naked Prophet eating his own shit or posing as Brigitte Bardot. They were so much better taking on the frisky College of Cardinals:

