[A]s [Gertrude] Stein relates in The Autobiography of Alice B Toklas, there was another visual influence on which Picasso fed voraciously when she first knew him in Paris in 1906, when he was pushing towards the most revolutionary artistic discovery since the Renaissance: a comic strip called The Katzenjammer Kids.
As Alice tells it, she and Stein were worried about Picasso and Fernande, his partner in these years, because they had broken up. So they went to see Picasso and Stein gave him a gift: a package of newspapers. “He opened them up, they were the Sunday supplement of American papers, they were the Katzenyammer [sic] kids. Oh oui, Oh oui, he said, his face full of satisfaction, merci thanks Gertrude, and we left.”
Next they went to see Fernande, who asked if Stein had any American comics left. But Picasso had got the lot of the Katzenjammer kids. “That is a brutality that I will never forgive him,” said Fernande.
From The Guardian’s preview of the 2002 Tate Modern Matisse Picasso exhibit.
And that just lends even more credence to the quote attributed to Picasso himself:
If there is one thing I regret in life, it is never having made comics.
(Which, after all, he did, so no regrets, Pablo!)