h. c. andersen, medusa, agnete lind picture book, 1854
In an 1833 letter about da Vinci's "Medusa" Andersen wrote:
The head had something magic about it that attracted me, the foam of the abyss in its most beautiful form; it is hell that has created a Madonna head, the warm poison streaming out of her mouth; the serpent's hair is moving while the beholder becomes petrified.
From Hans Christian Andersen as an Artist. The book's editor wasn't happy with the quality of the reproductions until the 2005 edition (70s issue -- with fewer pages -- is going super cheap online). The book begins with a quote from Van Gogh: "Don't you think Andersen's fairy tales are very beautiful? I am sure he must draw illustrations as well."
Read more about Andersen's art at Airform Archives.
The foam of the abyss!
h. c. andersen, here lies the serpent of knowledge, agnete lind picture book, 1855
"For here lies the Serpent of Knowledge / For better or for worse."
h. c. andersen, collage, jonas drewsen picture book, 1862
The two gentlemen enjoying a drive appear to also be enjoying each other.
h. c. andersen, a rectangle becomes a person, agnete lind picture book, 1857
Inscribed: "Do you see the red post by the gate? / Isn't he staring! He's nasty!"
Two of the stamp book images I scanned but left out of the original post for unknown reasons:
h.c. andersen, from astrid stampe's picture book, 1853
Inscribed: "Up goes the balloon! And the wife! Here are spectacles, gold and shiny / See through them and have a thought." and "Alas, when everything flies away / the outline of the heart goes black."